Quarterly Financial Information Disclosure [Abstract] Selected Quarterly Financial Information [Table] Selected Quarterly Financial Information [Table] Selected Quarterly Financial Information [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Stock [Member] Common Stock [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum [Member] Maximum [Member] Minimum [Member] Minimum [Member] Selected Quarterly Financial Information [Line Items] Selected Quarterly Financial Information [Line Items] [Line Items] for Selected Quarterly Financial Information [Table] Revenue Revenue, Net Operating income (loss) Operating Income (Loss) Income (loss) from continuing operations Income (Loss) from Continuing Operations Attributable to Parent Net income (loss) available for common stock Net Income (Loss) Available to Common Stockholders, Basic Total income (loss) per share, Basic (usd per share) Earnings Per Share, Basic Total income (loss) per share, Diluted (usd per share) Earnings Per Share, Diluted Dividends per share paid (usd per share) Common Stock, Dividends, Per Share, Cash Paid Share Price (usd per share) Stock Price Stock Price Supplemental Cash Flow Information [Abstract] Supplemental Disclosure of Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Cheyenne Light [Member] Cheyenne Light [Member] Cheyenne Light [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension Plans, Defined Benefit [Member] Pension Plan [Member] Supplemental Employee Retirement Plans, Defined Benefit [Member] Supplemental Employee Retirement Plan [Member] Other Postretirement Benefit Plans, Defined Benefit [Member] Other Postretirement Benefit Plan [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] Maximum Annual Contribution Per Employee, Percent Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Employers Matching Contribution, Annual Vesting Percentage Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage Employee Vesting Period Defined Contribution Plan, Employee Vesting Period Period over which an employee vests in a defined contribution plan. Pension and Other Postretirement Defined Benefit Plans, Liabilities [Abstract] Pension and Other Postretirement Defined Benefit Plans, Liabilities [Abstract] Defined Benefit Plan, Funded Status of Plan Defined Benefit Plan, Funded Status of Plan Defined Benefit Plan, Measurement Date Defined Benefit Plan, Measurement Date Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Income Tax Disclosure [Abstract] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Liability for Uncertain Tax Positions, Noncurrent, Period Start Liability for Uncertain Tax Positions, Noncurrent Additions for prior year tax positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Reductions for prior year tax positions Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Additions for current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Liability for Uncertain Tax Positions, Noncurrent, Period End Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Commitments and Contingencies Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Electric Utilities [Member] Electric Utilities [Member] Electric Utilities Segment [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Industrial Development Revenue Bonds Due 2027 [Member] Industrial Development Revenue Bonds Due 2027 [Member] Industrial Development Revenue Bonds Due 2027 [Member] Industrial Development Revenue Bonds Due 2021 [Member] Industrial Development Revenue Bonds Due 2021 [Member] Industrial Development Revenue Bonds Due 2021 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Long-term Debt Long-term Debt, Gross Long-term Debt, Maturity Date Debt Instrument, Maturity Date Segment Reporting Information, Additional Information [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Intercompany Eliminations [Member] Intersegment Eliminations [Member] Operating Segments [Member] Operating Segments [Member] Corporate, Non-Segment [Member] Corporate, Non-Segment [Member] Consolidation, Eliminations [Member] Consolidation, Eliminations [Member] Gas Utilities [Member] Gas Utilities [Member] Gas Utilities [Member] Power Generation [Member] Power Generation Coal Mining [Member] Coal Mining [Member] Coal Mining Oil and Gas [Member] Oil and Gas [Member] Oil and Gas [Member] Segment Reporting Information Segment Reporting Information [Line Items] Fuel, purchased power and cost of natural gas sold Fuel, Purchased Power and Cost of Gas Sold Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period, combined with the amount of purchased power charged against earnings for the period, and cost of gas sold to customers for the period. Operations and maintenance Costs and Expenses Depreciation, depletion and amortization Depreciation, Depletion and Amortization Impairment of long-lived assets Impairment of Long-Lived Assets Held-for-use Operating income Interest expense Interest Expense Unrealized gain (loss) on interest rate swaps, net Unrealized Gain (Loss) on Derivatives Interest income Investment Income, Interest Other income (expense), net Other Nonoperating Income (Expense) Impairment of equity investments Equity Method Investment, Other than Temporary Impairment Income tax benefit (expense) Income Tax Expense (Benefit) Income (loss) from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Guarantees [Abstract] Schedule of Guarantor Obligations [Table] Schedule of Guarantor Obligations [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Source Gas [Member] Source Gas [Member] Source Gas [Member] Guarantor Obligations by Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Surety Bond [Member] Performance Guarantee [Member] Performance Guarantee [Member] Project [Axis] Project [Axis] Project [Domain] Project [Domain] Peak View Wind Project [Member] Peak View Wind Project [Member] Peak View Wind Project [Member] Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Guarantor Obligations, Term Guarantor Obligations, Term Guarantor, Maximum Exposure Guarantor Obligations, Maximum Exposure, Undiscounted Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging [Member] Cash Flow Hedging [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap [Member] Interest Rate Swap [Member] Commodity derivatives [Member] Commodity Contract [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Unrealized Gain Loss on Interest Rate Swaps [Member] Unrealized Gain Loss on Interest Rate Swaps [Member] Unrealized Gain Loss on Interest Rate Swaps [Member] Interest Expense [Member] Interest Expense [Member] Sales Revenue, Goods, Net [Member] Sales Revenue, Goods, Net [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Summary of Cash Flow Hedge Activity [Abstract] Summary of Cash Flow Hedge Activity [Abstract] Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Derivative Instruments Not Designated as Hedging Instruments [Abstract] Derivative Instruments Not Designated as Hedging Instruments [Abstract] Amount of Gain/(Loss) on Derivatives Recognized in Income Derivative, Gain (Loss) on Derivative, Net Derivative [Table] Derivative [Table] Business Group [Axis] Business Group [Axis] Business Group (grouping of segments) [Axis] Business Group [Domain] Business Group [Domain] [Domain] for Business Group (grouping of segments) [Axis] Utilities Group [Member] Utilities Group [Member] Utilities Group - consists of our Electric Utilities and our Gas Utilities segments Derivative [Line Items] Derivative [Line Items] Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Contract or notional amounts and terms of marketing activities and derivative commodity instruments Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Table Text Block] Valuation and Qualifying Accounts [Abstract] Movement in Valuation Allowances and Reserves [Roll Forward] Allowance for Doubtful Accounts, Balance at Beginning of Year Valuation Allowances and Reserves, Balance Allowance for Doubtful Accounts, Adjustments Valuation Allowances and Reserves, Adjustments Allowance for Doubtful Accounts, Charged to Cost and Expense Valuation Allowances and Reserves, Charged to Cost and Expense Allowance for Doubtful Accounts, Recoveries and Other Additions Valuation Allowances and Reserves, Recoveries Allowance for Doubtful Accounts, Write-Offs and Other Deductions Valuation Allowances and Reserves, Deductions Allowance for Doubtful Accounts, Balance at End of Year Income Taxes Income Tax Disclosure [Text Block] Purchase Commitment, Excluding Long-term Commitment [Table] Purchase Commitment, Excluding Long-term Commitment [Table] Purchase Commitment, Excluding Long-term Commitment [Axis] Purchase Commitment, Excluding Long-term Commitment [Axis] Purchase Commitment, Excluding Long-term Commitment [Domain] Purchase Commitment, Excluding Long-term Commitment [Domain] Cargill Power Purchase Agreement [Member] Cargill Power Purchase Agreement [Member] Cargill Power Purchase Agreement [Member] Purchase Commitment, Excluding Long-term Commitment [Line Items] Purchase Commitment, Excluding Long-term Commitment [Line Items] Short-term Contract for Purchase of Electric Power, Date of Contract Expiration Short-term Contract for Purchase of Electric Power, Date of Contract Expiration Date of contract expiration of short-term contract to purchase electricity from a production plant, in CCYY-MM-DD format. Number of Megawatts Capacity Purchased Number of Megawatts Capacity Purchased Number of Megawatts being purchased under capacity and energy contract Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Common Stock, Par Value (usd per share) Common Stock, Par or Stated Value Per Share Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Treasury Stock, Shares Treasury Stock, Shares Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Asset Retirement Obligation Disclosure [Abstract] Asset Retirement Obligations Asset Retirement Obligation Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Ownership Percentage by Noncontrolling Owner Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Sale of Ownership Interest by Parent Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Sale of Interest by Parent Asset Retirement Obligations [Table] Asset Retirement Obligations [Table] Asset Retirement Obligations [Table] Asset Retirement Obligation Costs [Line Items] Costs provided for the retirement of certain long-live assets that are reasonably expected to be recovered in utility rates charged to customers [Line Items] Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Balance on January 1, Asset Retirement Obligation Liabilities Incurred Asset Retirement Obligation, Liabilities Incurred Liabilities Settled Asset Retirement Obligation, Liabilities Settled Accretion Expense Asset Retirement Obligation, Accretion Expense Revision of Prior Estimate Asset Retirement Obligation, Revision of Estimate Balance on December 31, Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Counterparty A [Member] Counterparty A [Member] Counterparty A [Member] Counterparty B [Member] Counterparty B [Member] Counterparty B [Member] Counterparty F [Member] Counterparty F [Member] Counterparty F [Member] Counterparty G [Member] Counterparty G [Member] Counterparty G [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Derivative Asset [Abstract] Derivative Asset [Abstract] Derivative Asset Derivative Asset Derivative, Collateral, Obligation to Return Cash Derivative, Collateral, Obligation to Return Cash Derivative Asset, after Netting and Cash Collateral Not Offset Within Derivative Assets Net Derivative Position, Assets The net derivative balance due from (or due to) a counterparty after cash collateral and counterparty netting is taken into account even if not offset in derivative accounts on Balance Sheet. Derivative Liability [Abstract] Derivative Liability [Abstract] Derivative Liability Derivative Liability Derivative, Collateral, Right to Reclaim Cash Derivative, Collateral, Right to Reclaim Cash Derivative Liability, After Netting and Cash Collateral Not Offset Within Derivative Liabilities Net Derivative Position, Liabilities The net derivative balance due to (or due from) a counterparty after cash collateral and counterparty netting is taken into account even if not offset in derivative accounts on Balance Sheet. Asset Impairment Charges [Abstract] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Willow Creek / Lodge Creek Pipeline And Gathering System [Member] Willow Creek / Lodge Creek Pipeline And Gathering System [Member] Willow Creek / Lodge Creek Pipeline And Gathering System [Member] Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Equity Method Investment, Other than Temporary Impairment Equity Method Investment, Realized Gain (Loss) on Disposal Equity Method Investment, Realized Gain (Loss) on Disposal Oil and Gas Exploration and Production Industries Disclosures [Abstract] Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] Standardized measure - beginning of year Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves Sales and transfers of oil and gas produced, net of production costs Sales and Transfers of Oil and Gas Produced, Net of Production Costs Net changes in prices and production costs Net Increase (Decrease) in Sales and Transfer Prices and Production Costs Extensions, discoveries and improved recovery, less related costs Extensions, Discoveries, Additions and Improved Recovery, Less Related Costs Changes in future development costs Changes in Estimated Future Development Costs Development costs incurred during the period Previously Estimated Development Costs Incurred Revisions of previous quantity estimates Revisions of Previous Quantity Estimates Accretion of discount Accretion of Discount Net change in income taxes Changes in Future Income Tax Expense Estimates on Future Cash Flows Related to Proved Oil and Gas Reserves Purchases of reserves Increase Due to Purchases of Minerals in Place Sales of reserves Decrease Due to Sales of Minerals in Place Standardized measure - end of year Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Domain] External Credit Rating by Grouping [Domain] External Credit Rating, Non Investment Grade [Member] External Credit Rating, Non Investment Grade [Member] Energy [Axis] Energy [Axis] Energy [Domain] Energy [Domain] Crude Oil [Member] Crude Oil [Member] Natural Gas [Member] Natural Gas [Member] Natural Gas, Distribution [Member] Natural Gas, Distribution [Member] Natural Gas for distribution [Member] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Swaps and Options [Member] Swaps and Options [Member] A forward-based contract in which two parties agree to swap streams of payments over a specified period, and an option contract in which the underlying asset is a commodity. Swap [Member] Swap [Member] Future [Member] Future [Member] Commodity Option [Member] Commodity Option [Member] Basis Swap [Member] Basis Swap [Member] Designated as Hedging Instrument [Member] Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Contract Type [Domain] Purchase Contract [Member] Purchase Contract [Member] Purchase Contract [Member] Credit Exposure, Non-investment Grade Company Credit Derivative, Maximum Exposure, Undiscounted Notional amount - commodities Derivative, Nonmonetary Notional Amount, Volume Notional amount - commodities Derivative, Nonmonetary Notional Amount, Energy Measure MaximumTerm Hedged in Cash Flow Hedge Maximum Length of Time Hedged in Cash Flow Hedge Derivative assets, current Derivative Asset, Current Derivative assets, non-current Derivative Asset, Noncurrent Derivative liabilities, current Derivative Liability, Current Derivative liabilities, non-current Derivative Liability, Noncurrent Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Maximum Term Derivative, Remaining Maturity Net Unrealized Gain (Loss) Included in Regulatory assets or Regulatory liabilities Net Unrealized Gain (Loss) Deferred, Regulated Operations Net Unrealized Gain (Loss) Included in Regulatory Assets or Regulatory Liabilities. Notional amount Derivative, Notional Amount Weighted average fixed interest rate Derivative, Average Fixed Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Unrecorded Unconditional Purchase Obligation [Table] Unrecorded Unconditional Purchase Obligation [Table] Category of Item Purchased [Axis] Category of Item Purchased [Axis] Long-term Purchase Commitment, Category of Item Purchased [Domain] Long-term Purchase Commitment, Category of Item Purchased [Domain] Wygen I Generating Facility [Member] Wygen I Generating Facility [Member] Jointly Owned Wygen I Generating Facility [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Purchase Option, Property [Member] Purchase Option, Property [Member] A contract between two parties, the buyer and the seller of the option, where the buyer has the right but not the obligation to buy a particular property, plant and equipment from the seller of the option at a certain time (the expiration date) for a certain price (the strike price). [Member] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unrecorded Unconditional Purchase Obligation [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Long-term Contract for Purchase of Electric Power, Date of Contract Expiration Long-term Contract for Purchase of Electric Power, Date of Contract Expiration Asset Purchase Option Asset Purchase Option The original fixed option amount per Megawatt to be paid to purchase property, plant and equipment in the future prior to any adjustments. Stockholders' Equity Note [Abstract] Schedule of Company's equity units Schedule of Capital Units [Table Text Block] Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Senior Unsecured Notes Due 2026 [Member] Senior Unsecured Notes Due 2026 [Member] Senior Unsecured Notes Due 2026 [Member] Senior Unsecured Notes Due 2019 [Member] Senior Unsecured Notes Due 2019 [Member] Senior Unsecured Notes Due 2019 Remarketable Junior Subordinated Notes Due 2028 [Member] Remarketable Junior Subordinated Notes Due 2028 [Member] Remarketable Junior Subordinated Notes Due 2028 [Member] Black Hills Corporation [Member] Black Hills Corporation [Member] Black Hills Corporation [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Business Combination, Purchase Price Business Combination, Consideration Transferred Business Combination, Capital Expenditures Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Debt Assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Long-term Debt, Fixed Interest Rate Debt Instrument, Interest Rate, Stated Percentage Debt instrument term Debt Instrument, Term Long-term debt - issuance Proceeds from Issuance of Long-term Debt Issuance of common stock, shares Stock Issued During Period, Shares, New Issues Issuance of common stock Stock Issued During Period, Value, New Issues Debt Instrument, Convertible, Number of Equity Instruments Debt Instrument, Convertible, Number of Equity Instruments Equity units - issuance Proceeds from Sale of Interest in Corporate Unit Bridge Loan Bridge Loan Number of natural gas utilities acquired Number Of Natural Gas Utilities Acquired Number Of Natural Gas Utilities Acquired Number of customers served with acquisition Number Of Customers Acquired Number Of Customers Acquired Length of natural gas pipeline (miles) Length Of Natural Gas Pipeline Acquired Length Of Natural Gas Pipeline Acquired Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Supplemental Employee Retirement Plan [Member] Other Postretirement Benefit Plan [Member] Healthcare trend rate pre-65 Healthcare trend rate post-65 Black Hills Utility Holdings [Member] Black Hills Utility Holdings dba as Black Hills Energy [Member] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Discount Rate, Benefit Obligation Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Rate of Increase in Compensation Levels Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Discount Rate, Net Periodic Cost Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected Long-term Return on Assets Rate of Compensation Increase Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Defined Benefit Plan Assumptions Used In Calculating Net Periodic Benefit Cost Expected Rate of Return On Assets For Next Fiscal Year Defined Benefit Plan Assumptions Used In Calculating Net Periodic Benefit Cost Expected Rate of Return On Assets For Next Fiscal Year An assumption for the next fiscal year as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] Trend for next year Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year Ultimate trend rate Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Year Ultimate Trend Reached Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Effect of One Percentage Point Increase on Service and Interest Cost Components Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components Effect of One Percentage Point Decrease on Service and Interest Cost Components Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components Statement of Stockholders' Equity [Abstract] Treasury Stock [Member] Treasury Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Shares, Issued Period Start Shares, Issued Stockholders' Equity Attributable to Parent Period Start Stockholders' Equity Attributable to Parent Treasury Stock, Shares, Period Start Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax Dividends on common stock, shares Common Stock Dividends, Shares Dividends on common stock Dividends, Common Stock, Cash Share-based compensation, shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Share-based compensation Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Tax effect of share-based compensation Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Issuance costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Premium on Equity Units Premium on Publicly-Traded Equity Units Known As Corporate Units Premium on Publicly-Traded Equity Units Known As Corporate Units Dividend reinvestment and stock purchase plan, shares Stock Issued During Period, Shares, Dividend Reinvestment Plan Dividend reinvestment and stock purchase plan Stock Issued During Period, Value, Dividend Reinvestment Plan Other stock transactions, shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) Other stock transactions Stockholders' Equity, Other Shares, Issued Period End Stockholders' Equity Attributable to Parent Period End Treasury Stock, Shares, Period End Dividends, Common Stock [Abstract] Dividends, Common Stock [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Derivative Assets, Commodity Derivatives Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset Derivative Assets, Total Assets, Fair Value Disclosure Derivative, Liabilities, Fair Value Disclosure Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset Derivative Liabilities, Total Financial and Nonfinancial Liabilities, Fair Value Disclosure Fair Value, Transfers Between Level 1 and Level 2, Description and Policy [Abstract] Fair Value, Transfers Between Level 1 and Level 2, Description and Policy [Abstract] Assets-Transfers out of level 1 to 2 Fair Value, Assets, Level 1 to Level 2 Transfers, Amount Assets -Transfers out of level 2 to 1 Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Liabilities -Transfers out of level 1 to 2 Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Liabilities -Transfers out of level 2 to 1 Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] State and Local Jurisdiction [Member] State and Local Jurisdiction [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Summary of Operating Loss Carryforwards Summary of Operating Loss Carryforwards [Table Text Block] Summary of Income Tax Contingencies Summary of Income Tax Contingencies [Table Text Block] Summary of State Tax Carryforwards Summary of Tax Credit Carryforwards [Table Text Block] Long-term Debt, Unclassified [Abstract] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Black Hills Power [Member] Black Hills Power [Member] Black Hills Power [Member] Senior Unsecured Notes Due 2023 [Member] Senior Unsecured Notes Due 2023 [Member] [Member] Senior Unsecured Notes Due 2023 [Member] Senior Unsecured Notes Due 2020 [Member] Senior Unsecured Notes Due 2020 [Member] Senior Unsecured Notes Due 2020 [Member] Corporate Term Loan Due April 2017 [Member] Corporate Term Loan Due April 2017 [Member] Corporate Term Loan Due April 2017 [Member] Corporate Term Loan due June 2015 [Member] Corporate Term Loan Due June 2015 [Member] Corporate Term Loan Due June 2015 First Mortgage Bonds Due 2044 [Member] First Mortgage Bonds Due 2044 [Member] First Mortgage Bonds Due 2044 [Member] First Mortgage Bonds Due 2032 [Member] First Mortgage Bonds Due 2032 [Member] First Mortgage Bonds Due 2032 [Member] First Mortgage Bonds Due 2039 [Member] First Mortgage Bonds Due 2039 [Member] First Mortgage Bonds Due 2039 [Member] First Mortgage Bonds Due 2037 [Member] First Mortgage Bonds Due 2037 [Member] First Mortgage Bonds Due 2037 [Member] Series 94 A Debt, Due 2024 [Member] Bonds Due 2024 [Member] Bonds Due 2024 [Member] Long-term Debt, Variable Interest Rate Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate Debt Instrument, Unamortized Discount Debt Instrument, Unamortized Discount Long-term Debt, including current maturities Long-term Debt Long-term Debt, Current Maturities Long-term Debt, Current Maturities Long-term debt, net of current maturities Long-term Debt, Excluding Current Maturities Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Dividend Reinvestment Plan [Member] Dividend Reinvestment and Stock Purchase Plan [Member] Dividend Reinvestment and Stock Purchase Plan [Member] Class of Stock [Line Items] Class of Stock [Line Items] Percent of recent average market price Common Stock Purchase Percentage of Recent Average Market Price Common stock purchase percentage of recent average market price Shares Issued Weighted Average Price (usd per share) Dividend Reinvestment Plan, Weighted Average Price Weighted Average Price per Share for shares issued under the Dividend Reinvestment Plan Unissued Shares Available Common Stock, Capital Shares Reserved for Future Issuance Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Total Current Current Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Tax credit amortization Investment Tax Credit Amortization Investment Tax Credit Amortization - The amount deducted from an entity taxes, reflecting a percentage of an amount invested in a certain assets spread over the useful life of those assets: includes deferred investment tax credits. Total Deferred Deferred Income Tax Expense (Benefit) Total Non-cash Investing and Financing Activities from Continuing Operations [Abstract] Noncash Investing and Financing Items [Abstract] Property, plant and equipment acquired with accrued liabilities Capital Expenditures Incurred but Not yet Paid Increase (decrease) in capitalized assets associated with asset retirement obligations Non-cash Revision to Capitalized Asset Retirement Costs The amount of non-cash revision to property, plant and equipment for capitalized asset retirement costs Cash (paid) refunded during the period for continuing operations [Abstract] Supplemental Cash Flow Elements [Abstract] Interest (net of amounts capitalized) Interest Paid, Net Income taxes, net Income Taxes Paid, Net Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block] Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block] Schedule of Oil and Gas In Process Activities Schedule of Oil and Gas In Process Activities [Table Text Block] Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block] Results of Operations for Oil and Gas Producing Activities Disclosure Results of Operations for Oil and Gas Producing Activities Disclosure [Table Text Block] Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization [Table Text Block] Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block] Changes In Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserve Disclosures Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows [Table Text Block] Future cash inflows Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Cash Inflows Future production costs Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Production Costs Future development costs, including plugging and abandonment Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Development Costs Future income tax expense Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Income Tax Expense Future net cash flows Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Net Cash Flows 10% annual discount for estimated timing of cash flows Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Ten Percent Annual Discount for Estimated Timing of Cash Flows Standardized measure of discounted future net cash flows Quarterly Historical Data (Unaudited) Quarterly Financial Information [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Energy Marketing [Member] Energy Marketing [Member] Energy Marketing Disposal Date Disposal Date Polution Control Revenue Bonds Due 2024 [Member] Polution Control Revenue Bonds Due 2024 [Member] Polution Control Revenue Bonds Due 2024 [Member] Extinguishment of Debt, Amount Extinguishment of Debt, Amount Jointly Owned Facilities Jointly Owned Facilities, Utility and Non-Regulated [Text Block] Disclosure of proportionate interests in jointly owned facilities (regulated utiliyt and non-regulated). Includes the amount of plants in service, the accumulated depreciation (if available), the amount of construction in progress, and the proportionate share. Includes statements that the amounts represent the company's share in each joint facility and that it must provide its own financing. States that the company's share of direct expenses of the joint facilities is included in the corresponding operating expenses on its income statement (for example, fuel, maintenance, other operating expense). [Text Block] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Deferred Financing Costs Deferred Financing Costs [Table Text Block] Schedule of Deferred Financing Costs expensed on the Statement of Income and/or net amount presented on the Statement of Financial Position [Table Text Block] Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Projected Benefit Obligation at Beginning of Year Defined Benefit Plan, Benefit Obligation Service Cost Defined Benefit Plan, Service Cost Interest Cost Defined Benefit Plan, Interest Cost Actuarial (Gain) Loss Defined Benefit Plan, Actuarial Gain (Loss) Benefits Paid Defined Benefit Plan, Benefits Paid Defined Benefit Plan, Benefit Obligation Benefits Paid Defined Benefit Plan Benefits Paid from Company Assets Defined Benefit Plan Benefits Paid from Company Assets Benefits Paid Defined Benefit Plan Benefits Paid From Plan and Company Assets Defined Benefit Plan Benefits Paid From Plan and Company Assets Medicare Part D Accrued Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received Plan Participants' Contributions Defined Benefit Plan, Contributions by Plan Participants Projected Benefit Obligation at End of Year Defined Benefit Plan, One Time Lump Sum Benefit Paid Defined Benefit Plan, One Time Lump Sum Benefit Paid A one time lump sum benefit payment paid to certain eligible terminated vested participants. This payment reduces plan assets. Schedule of Guarantor Obligations Schedule of Guarantor Obligations [Table Text Block] Senior Unsecured Notes Due 2023 [Member] [Member] Senior Unsecured Notes Due 2014 [Member] Senior Unsecured Notes Due 2014 [Member] Senior Unsecured Notes Due 2014 [Member] Bridge Term Loan Bridge Term Loan - July 2015 [Member] Bridge Term Loan - July 2015 [Member] Project Financing Debt Due 2016 [Member] Project Financing Debt Due 2016 [Member] Project Financing Debt Due 2016 [Member] Deferred Financing Costs, Other [Member] Deferred Financing Costs, Other [Member] Aggregate amount of deferred financing costs that is associated with Long-Term Debt not separately identified due to immateriality of each individual debt. Deferred Finance Costs Remaining, Noncurrent Deferred Finance Costs, Noncurrent, Net Amortization Expense for Deferred Financing Costs Amortization of Financing Costs Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Foreign Tax Authority [Member] Foreign Tax Authority [Member] Internal Revenue Service (IRS) [Member] Internal Revenue Service (IRS) [Member] Nature of Uncertainty [Axis] Nature of Uncertainty [Axis] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Settlement with Taxing Authority [Member] Settlement with Taxing Authority [Member] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Foreign Tax Credit Carryforward [Member] Foreign Tax Credit Carryforward [Member] Foreign Tax Credit Carryforward [Member] Investment Tax Credit Carryforward [Member] Investment Tax Credit Carryforward [Member] Research Tax Credit Carryforward [Member] Research Tax Credit Carryforward [Member] Deferred Tax Asset [Domain] State Tax Credit [Member] State Tax Credit [Member] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Other Tax Carryforward, Gross Amount Tax Credit Carryforward, Amount Tax Credit Carryforward, Expiration Date Tax Credit Carryforward, Expiration Date Tax Credit Carryforward, Valuation Allowance Tax Credit Carryforward, Valuation Allowance Income Tax Examination, Year under Examination Income Tax Examination, Year under Examination Deferred Tax Assets, State Tax Credits Deferred Tax Assets, State Taxes Valuation Allowance, Deferred Tax Asset, Change in Amount Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Income Tax Expense (Benefit) Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Employee Stock Option [Member] Employee Stock Option [Member] Restricted Stock [Member] Restricted Stock [Member] Performance Shares [Member] Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Share-based Compensation, Stock Options, Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Disclosure of Share-based Compensation Arrangements by Share-based Payment Award Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity Schedule of Dividend Reinvestment Plan [Table Text Block] Schedule describing activity for a dividend reinvestment plan [Table Text Block] Jointly Owned Utility Plant Interests [Table] Jointly Owned Utility Plant Interests [Table] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Domain] Jointly Owned Utility Plant [Domain] Wyodak Plant [Member] Wyodak Plant - power generation plant owned 20% by Black Hills Power and 80% by Pacificorp[Member] Transmission Tie [Member] Jointly onwed Transmission Tie [Member] Wygen I I I Generating Facility [Member] Wygen I I I Generating Facility [Member] Wygen I I I - Black Hills Power's coal-fired power generation plant that commenced operations on April 1, 2010.[Member] Busch Ranch Wind Farm [Member] Busch Ranch Wind Farm [Member] Busch Ranch Wind Project [Member] Jointly Owned Utility Plant Interests [Line Items] Jointly Owned Utility Plant Interests [Line Items] Ownership Share Percentage Jointly Owned Utility Plant, Proportionate Ownership Share Ownership Amount of Plant in Service Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service Ownership Amount of Construction Work in Progress Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress Ownership Amount of Plant Accumulated Depreciation Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation Statement of Comprehensive Income [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Cash Flow Hedging Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) [Member] Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification out of Accumulated Other Comprehensive Income [Member] Interest Rate Contract [Member] Interest Rate Contract [Member] Commodity Contract [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] Interest expense Interest Costs Incurred Income (loss) from continuing operations before earnings (loss) of unconsolidated subsidiaries and income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Utilities - Operations and maintenance Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses Non-regulated energy operations and maintenance Operating Costs, Nonregulated Energy Operations Operating costs related to fuel, operations and maintenance, general and administrative costs excluding costs of regulated operations. This excluded the expenses related to certain taxes such as property, production and severance taxes. Net income (loss) available for common stock Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Notes Payable [Abstract] Schedule of Short-term Debt Schedule of Short-term Debt [Table Text Block] Schedule of Credit Facility Covenants Credit Facility and Short Term Debt Covenants [Table Text Block] Schedule of significant debt covenants related to Credit Facility and other short-term debt [Table Text Block] Fair value of financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Segment information included in Consolidated Balance Sheets Reconciliation of Assets from Segment to Consolidated [Table Text Block] Segment information included in Consolidated Statements of Income Schedule of Segment Reporting Information, by Segment [Table Text Block] Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Postretirement Health Coverage [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Schedule of Defined Contribution Plans Contributions Schedule of Employer Contribution to Employee Benefit Plans [Table Text Block] Schedule of Employer Contribution to Defined Benefit and Defined Contribution Plans [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Recurring Basis Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block] Schedule of Changes in Projected Benefit Obligations Schedule of Changes in Projected Benefit Obligations [Table Text Block] Schedule of Changes in Fair Value of Plan Assets Schedule of Changes in Fair Value of Plan Assets [Table Text Block] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Schedule of Accumulated and Projected Benefit Obligations Schedule of Accumulated and Projected Benefit Obligations [Table Text Block] Components of net periodic benefit cost Schedule of Net Benefit Costs [Table Text Block] Schedule of Net Periodic Benefit Cost Not yet Recognized Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block] Schedule of Assumptions Used Schedule of Assumptions Used [Table Text Block] Schedule of Health Care Cost Trend Rates Schedule of Health Care Cost Trend Rates [Table Text Block] Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] Schedule of Expected Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Schedule of Accounts Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts Receivable by Billing Status, Type [Axis] Billing Status, Type [Axis] Receivables Billing Status [Domain] Receivables Billing Status [Domain] Billed Revenues [Member] Billed Revenues [Member] Unbilled Revenues [Member] Unbilled Revenues [Member] Accounts Receivable by Business Segment of Entity, Type [Axis] Accounts Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts Receivable, Trade Accounts Receivable, Gross, Current Allowance for Doubtful Accounts Allowance for Doubtful Accounts Receivable, Current Accounts receivable, net Accounts Receivable, Net, Current Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Roll Forward] Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End Schedule of Jointly Owned Utility Plants Schedule Of Jointly Owned Facilities [Table Text Block] Tabular disclosure of proportionate interests in jointly owned plants. Includes the amount of plants in service, the accumulated provision for depreciation (if available), the amount of facilities under construction, and the proportionate share. Includes statements that the amounts represent the company's share in each joint plant and that it must provide its own financing. Information concerning two or more plants on the same site may be combined. States that the company's share of direct expenses of the joint facilities is included in the corresponding operating expenses on its income statement (for example, maintenance and other operating expense). This schedule includes both Utility and non-Utility facilities. [Table Text Block] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Corporate Debt Securities [Member] Corporate Debt Securities [Member] Debt Instrument, Maturity Date Debt Instrument, Increase (Decrease), Other, Net Debt Instrument, Increase (Decrease), Other, Net Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate Oil and Gas Reserves (Unaudited) Oil and Gas Exploration and Production Industries Disclosures [Text Block] Guarantees Guarantees [Text Block] Regulatory assets Regulatory Assets Current liabilities Pension and Other Postretirement Defined Benefit Plans, Current Liabilities Non-current assets Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Non-current liabilities Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Regulatory liabilities Regulatory Liabilities Business Description Segment Reporting, Policy [Policy Text Block] Use of Estimates and Basis of Presentation Use of Estimates, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Cash and Cash Equivalents, Restricted Cash and Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Accounts Receivable and Allowance for Doubtful Accounts Trade and Other Accounts Receivable, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Materials, Supplies and Fuel Inventory, Policy [Policy Text Block] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Oil and Gas Operations Industry Specific Policies, Oil and Gas [Policy Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Asset Retirement Obligations Asset Retirement Obligations, Policy [Policy Text Block] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Derivatives and Hedging Activities Derivatives, Policy [Policy Text Block] Derivatives, Offsetting Fair Value Amounts Derivatives, Offsetting Fair Value Amounts, Policy [Policy Text Block] Deferred Financing Costs Debt, Policy [Policy Text Block] Development Costs Property, Plant and Equipment, Preproduction Design and Development Costs [Policy Text Block] Legal Costs Legal Costs, Policy [Policy Text Block] Regulatory Accounting Public Utilities, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Earnings per Share of Common Stock Earnings Per Share, Policy [Policy Text Block] Discontinued Operations Discontinued Operations, Policy [Policy Text Block] Recently Issued and Adopted Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Stock Stockholders' Equity Note Disclosure [Text Block] Supplemental Disclosure of Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Statement of Financial Position [Abstract] Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash and equivalents Restricted Cash and Investments, Current Materials, supplies and fuel Inventory, Net Income tax receivable, net Income Taxes Receivable, Current Deferred income tax assets, net, current Deferred Tax Assets, Net of Valuation Allowance, Current Regulatory assets, current Regulatory Assets, Current Other current assets Other Assets, Current Total current assets Assets, Current Investments Long-term Investments Property, plant and equipment Property, Plant and Equipment, Gross Less accumulated depreciation and depletion Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total property, plant and equipment, net Property, Plant and Equipment, Net Other assets: Other Assets, Noncurrent [Abstract] Goodwill Goodwill Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Derivative assets, non-current Regulatory assets, non-current Regulatory Assets, Noncurrent Other assets, non-current Other Assets, Noncurrent Total other assets, non-current Assets, Noncurrent TOTAL ASSETS Assets Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Regulatory liabilities, current Regulatory Liability, Current Notes payable Short-term Debt Current maturities of long-term debt Total current liabilities Liabilities, Current Deferred credits and other liabilities: Liabilities, Noncurrent [Abstract] Deferred income tax liabilities, net, non-current Deferred Tax Liabilities, Net, Noncurrent Regulatory liabilities, non-current Regulatory Liability, Noncurrent Benefit plan liabilities Other deferred credits and other liabilities Other Liabilities, Noncurrent Total deferred credits and other liabilities Liabilities, Noncurrent Commitments and contingencies (See Notes 2, 6, 7, 8, 9, 14, 18, 19, and 20) Commitments and Contingencies Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock $1 par value; 100,000,000 shares authorized; issued: 51,231,861 and 44,714,072 shares, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Treasury stock at cost - 39,720 and 42,226 shares, respectively Treasury Stock, Value Accumulated other comprehensive income (loss) Total stockholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities [Table] Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities [Table] Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items] Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items] Costs Incurred, Acquisition of Oil and Gas Properties [Abstract] Costs Incurred, Acquisition of Oil and Gas Properties [Abstract] Proved Reserves Costs Incurred, Acquisition of Oil and Gas Properties with Proved Reserves Unproved Reserves Costs Incurred, Acquisition of Unproved Oil and Gas Properties Exploration Costs Costs Incurred, Exploration Costs Development Costs Costs Incurred, Development Costs Asset Retirement Obligation Incurred Costs Incurred, Asset Retirement Obligation Incurred Oil and Gas Property Acquisition, Exploration, and Development Activities Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities Revolving Credit Facility [Table] Line of Credit Facility [Table] Base Rate Borrowings [Member] Base Rate [Member] Eurodollar Borrowings [Member] Eurodollar [Member] Letters of Credit [Member] Letter of Credit [Member] Revolving Credit Facility [Line Items] Line of Credit Facility [Line Items] Balance Outstanding Current Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Expiration Date Line of Credit Facility, Expiration Date Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Interest Rate at Period End Line of Credit Facility, Interest Rate at Period End Commitment Fee Percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Letters of Credit Outstanding Letters of Credit Outstanding, Amount Deferred Finance Costs [Abstract] Deferred Finance Costs [Abstract] Deferred Finance Costs, Noncurrent, Gross Deferred Finance Costs, Noncurrent, Gross Deferred Finance Costs, Noncurrent, Net Debt Covenants Disclosure [Abstract] Debt Disclosure [Abstract] Covenant Requirement - Recourse Leverage Ratio, Actual Recourse Leverage Ratio Recourse Leverage Ratio Covenant Requirement - Recourse Leverage Ratio, Maximum Debt Instrument, Covenant, Maximum Recourse Ratio The maximum allowed recourse leverage ratio under debt covenants. Netting Contract by Category [Axis] Netting Contract, Category [Axis] Netting Contract by Category [Axis] Netting Contract by Category [Domain] Netting Contract, Category [Domain] [Domain] for Netting Contract by Category [Axis] Contract Subject to Master Netting Arrangement [Member] Contract Subject to Master Netting Arrangement [Member] Contract Subject to Master Netting Arrangement [Member] Contract Not Subject to Master Netting Arrangement [Member] Contract Not Subject to Master Netting Arrangement [Member] Contract Not Subject to Master Netting Arrangement [Member] Derivative Asset, Fair Value, Gross Asset Derivative Asset, Fair Value, Gross Asset Gross Amounts Offset In Statement Of Financial Position Assets Gross Amounts Offset In Statement Of Financial Position Assets The gross amount of assets offset to determine the net amounts presented in the statement of financial position. Derivative Asset Derivative Liability, Fair Value, Gross Liability Derivative Liability, Fair Value, Gross Liability Gross Amounts Offset In Statement Of Financial Position Liabilities Gross Amounts Offset In Statement Of Financial Position Liabilities The gross amount of liabilities offset to determine the net amounts presented in the statement of financial position Derivative Liability Proceeds from Sale of Interest in Corporate Unit Proceeds from Convertible Debt Equity Unit Stated Amount (usd per share) Debt Instrument, Convertible, If Applicable Market Value Greater Than Reference Price, Amount Used To Calculate Number of Shares, Numerator Debt Instrument, Convertible, If Applicable Market Value Greater Than Reference Price, Amount Used To Calculate Number of Shares, Numerator Corporate Units Ownership Interest Percentage In Subordinated Notes Corporate Units Ownership Interest Percentage In Subordinated Notes Corporate Units Ownership Interest Percentage In Subordinated Notes Debt Instrument, Subordinated Notes, Stated Principal Amount Debt Instrument, Convertible Conversion Ratio Basis, Stated Principal Amount The base principal amount of debt on which the conversion ratio is calculated. Debt Instrument, Convertible, Threshold Consecutive Trading Days Debt Instrument, Convertible, Consecutive Trading Days for Calculation of Applicable Market Value Debt Instrument, Convertible, Consecutive Trading Days for Calculation of Applicable Market Value Debt Instrument, Convertible, Conversion Price (usd per share) Debt Instrument, Convertible, Conversion Price Debt Instrument, Convertible, Conversion Ratio Debt Instrument, Convertible, Conversion Ratio Debt Instrument, Convertible, Reference Price (usd per share) Debt Instrument, Convertible, Reference Price Debt Instrument, Convertible, Reference Price RSN Interest Rate Stock Purchase Contract Rate Equity Unit, Dividend Rate, Percentage, Annual Equity Unit, Dividend Rate, Percentage (annual) Equity Unit, Annual Dividend Amount (usd per share) Equity Unit, Annual Dividend Amount Equity Unit, Annual Dividend Amount Stock Purchase Contract Liability Debt Instrument, Convertible, Present Value Of Future Contract Adjustment Payments Debt Instrument, Convertible, Present Value Of Future Contract Adjustment Payments Capitalized Costs of Unproved Properties Excluded from Amortization [Table] Capitalized Costs of Unproved Properties Excluded from Amortization [Table] Capitalized Costs of Unproved Properties Excluded from Amortization by Property or Project [Axis] Unproved Oil and Gas Property or Major Project [Domain] Current Year [Member] Current Year [Member] Current Year [Member] Prior Year [Member] Prior Year [Member] Prior Year [Member] More Than One Year, Less Than Two Years Prior [Member] More Than One Year, Less Than Two Years Prior [Member] More Than One Year, Less Than Two Years Prior [Member] More Than Two Years Prior [Member] More Than Two Years Prior [Member] More Than Two Years Prior [Member] Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items] Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items] Interest Costs, Capitalized During Period Interest Costs Capitalized Leasehold acquisition cost Acquisition Costs, Period Cost Exploration cost Exploration Costs, Period Cost Capitalized interest Capitalized Interest Of Cost Excluded From Amortization The amount of the capitalized interest incurred during the period of unproved properties excluded from amortization. Total Capitalized Costs of Unproved Properties Excluded from Amortization, Period Cost Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Benefit plan liability adjustments - net gain (loss) (net of tax of $(1,375), $5,004 and $(3,813), respectively) Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Benefit plan liability adjustments - prior service (costs) (net of tax of $0, $(17) and $185, respectively) Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, Net of Tax Reclassification adjustment of benefit plan liability - net gain (loss) (net of tax of $(972), $(348) and $(971), respectively) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Reclassification adjustment of benefit plan liability - prior service cost (net of tax of $88, $76 and $88, respectively) Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), Net of Tax Fair value adjustment on derivatives designated as cash flow hedges (net of tax of $(4,496), $(5,239) and $(2,445), respectively) Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification adjustment of cash flow hedges settled and included in net income (loss) (net of tax of $4,271, $(2,344) and $(2,016), respectively) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Other comprehensive income (loss), net of tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Valuation Allowance by Deferred Tax Asset [Axis] Valuation Allowance by Deferred Tax Asset [Axis] Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] Valuation Allowance, Operating Loss Carryforwards [Member] Valuation Allowance, Operating Loss Carryforwards [Member] Operating Loss Carryforwards Operating Loss Carryforwards Expiration Dates Operating Loss Carryforwards, Expiration Date Operating Loss Carryforwards Valuation Allowance Operating Loss Carryforwards, Valuation Allowance Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Equity Securities [Member] Equity Securities [Member] Real Estate [Member] Real Estate [Member] Fixed Income Funds [Member] Fixed Income Funds [Member] Cash and Cash Equivalents [Member] Cash and Cash Equivalents [Member] Hedge Funds Hedge Funds, Multi-strategy [Member] Defined Benefit Plan, Target Allocation Percentage of Assets Defined Benefit Plan, Target Plan Asset Allocations AXA Equitable General Fixed Income Common Collective Trust - Cash and Cash Equivalents Common Collective Trust, Money Market Fund [Member] Investment in Common Collective Trusts, Money Market Fund [Member] Common Collective Trust - Equity Common Collective Trust, Equity Fund [Member] Common Collective Trust, Equity Fund [Member] Common Collective Trust - Fixed Income Common Collective Trust, Fixed Income Fund [Member] Common Collective Trued, Fixed Income Fund [Member] Common Collective Trust - Real Estate Real Estate Funds [Member] Fair Value, Inputs, Level 1 [Member] Defined Benefit Plan, Fair Value of Plan Assets Defined Benefit Plan, Fair Value of Plan Assets Statement of Cash Flows [Abstract] Operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) available for common stock (Income) loss from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Income (loss) from continuing operations Adjustments to reconcile income (loss) from continuing operations to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Deferred financing cost amortization Amortization of Financing Costs and Discounts Impairment of long-lived assets and equity method investments Impairment of Oil and Gas Properties Stock compensation Share-based Compensation Unrealized (gain) loss on interest rate swaps, net Deferred income taxes Employee benefit plans Pension and Other Postretirement Benefit Expense Other adjustments, net Other Noncash Income (Expense) Change in certain operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Materials, supplies and fuel Increase (Decrease) in Inventories Accounts receivable, unbilled revenues and other current assets Increase (Decrease) in Accounts Receivable and Other Operating Assets Accounts payable and other current liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Regulatory assets Increase (Decrease) in Other Regulatory Assets Regulatory liabilities Increase (Decrease) in Regulatory Liabilities Contributions to defined benefit pension plans Pension Contributions Other operating activities, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities of continuing operations Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash (used in) operating activities of discontinued operations Cash Provided by (Used in) Operating Activities, Discontinued Operations Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Property, plant and equipment additions Payments to Acquire Property, Plant, and Equipment Acquisition of net assets Payments to Acquire Businesses, Gross Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash provided by (used in) investing activities of continuing operations Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash provided by (used in) investing activities of discontinued operations Cash Provided by (Used in) Investing Activities, Discontinued Operations Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Dividends paid on common stock Payments of Dividends Common stock issued Proceeds from Issuance of Common Stock Short-term borrowings - issuances Proceeds from Lines of Credit Short-term borrowings - repayments Repayments of Lines of Credit Long-term debt - repayments Repayments of Long-term Debt De-designated interest rate swap settlement Payments for Derivative Instrument, Financing Activities Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash provided by (used in) financing activities of continuing operations Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash provided by (used in) financing activities of discontinued operations Cash Provided by (Used in) Financing Activities, Discontinued Operations Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net change in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents: Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Cash and cash equivalents beginning of year Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations Cash and cash equivalents end of year Notes Payable