2107100 - Disclosure - Accounts Receivable: link:presentationLink link:calculationLink link:definitionLink 2407402 - Disclosure - Accounts Receivable (Details) link:presentationLink link:calculationLink link:definitionLink 2307301 - Disclosure - Accounts Receivable (Tables) link:presentationLink link:calculationLink link:definitionLink 2127100 - Disclosure - Accrued Liabilities: link:presentationLink link:calculationLink link:definitionLink 2427402 - Disclosure - Accrued Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 2327301 - Disclosure - Accrued Liabilities (Tables) link:presentationLink link:calculationLink link:definitionLink 2106100 - Disclosure - Business Segment Information: link:presentationLink link:calculationLink link:definitionLink 2406402 - Disclosure - Business Segment Information: Information Relating to Segment Statement of Income (Details) link:presentationLink link:calculationLink link:definitionLink 2406403 - Disclosure - Business Segment Information: Segment and Corporate Assets (Details) link:presentationLink link:calculationLink link:definitionLink 2306301 - Disclosure - Business Segment Information (Tables) link:presentationLink link:calculationLink link:definitionLink 2123100 - Disclosure - Commitments and Contingencies: link:presentationLink link:calculationLink link:definitionLink 2423401 - Disclosure - Commitments and Contingencies: Dividend Restrictions (Details) link:presentationLink link:calculationLink link:definitionLink 1004000 - Statement - Condensed Consolidated Balance Sheets (unaudited) link:presentationLink link:calculationLink link:definitionLink 1004001 - Statement - Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 1005000 - Statement - Condensed Consolidated Statements of Cash Flows (unaudited) link:presentationLink link:calculationLink link:definitionLink 1003000 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited) link:presentationLink link:calculationLink link:definitionLink 1003001 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 1002000 - Statement - Condensed Consolidated Statements of Income (unaudited) link:presentationLink link:calculationLink link:definitionLink 1002000 - Statement - Condensed Consolidated Statements of Income (unaudited) link:presentationLink link:calculationLink link:definitionLink 2124100 - Disclosure - Discontinued Operations: link:presentationLink link:calculationLink link:definitionLink 2424402 - Disclosure - Discontinued Operations (Details) link:presentationLink link:calculationLink link:definitionLink 2324301 - Disclosure - Discontinued Operations (Tables) link:presentationLink link:calculationLink link:definitionLink 0001000 - Document - Document and Entity Information Document link:presentationLink link:calculationLink link:definitionLink 2112100 - Disclosure - Earnings Per Share: link:presentationLink link:calculationLink link:definitionLink 2412403 - Disclosure - Earnings Per Share: Anti-dilutive shares (Details) link:presentationLink link:calculationLink link:definitionLink 2412402 - Disclosure - Earnings Per Share: Earnings Per Share Reconciliation (Details) link:presentationLink link:calculationLink link:definitionLink 2312301 - Disclosure - Earnings Per Share (Tables) link:presentationLink link:calculationLink link:definitionLink 2122100 - Disclosure - Employee Benefit Plans: link:presentationLink link:calculationLink link:definitionLink 2422402 - Disclosure - Employee Benefit Plans (Details) link:presentationLink link:calculationLink link:definitionLink 2322301 - Disclosure - Employee Benefit Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 2115100 - Disclosure - Equity: link:presentationLink link:calculationLink link:definitionLink 2415403 - Disclosure - Equity: At-the-Market Equity Offering Program (Details) link:presentationLink link:calculationLink link:definitionLink 2415404 - Disclosure - Equity: Dividends on Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 2415402 - Disclosure - Equity: Stockholders Equity Recap (Details) link:presentationLink link:calculationLink link:definitionLink 2315301 - Disclosure - Equity (Tables) link:presentationLink link:calculationLink link:definitionLink 2117100 - Disclosure - Fair Value Measurements: link:presentationLink link:calculationLink link:definitionLink 2417403 - Disclosure - Fair Value Measurements: Balance Sheet Location (Details) link:presentationLink link:calculationLink link:definitionLink 2417402 - Disclosure - Fair Value Measurements: Schedule of Fair Values (Details) link:presentationLink link:calculationLink link:definitionLink 2317301 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 2119100 - Disclosure - Fair Value of Financial Instruments: link:presentationLink link:calculationLink link:definitionLink 2419402 - Disclosure - Fair Value of Financial Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 2319301 - Disclosure - Fair Value of Financial Instruments (Tables) link:presentationLink link:calculationLink link:definitionLink 2126100 - Disclosure - Income Taxes: link:presentationLink link:calculationLink link:definitionLink 2426401 - Disclosure - Income Taxes (Details) link:presentationLink link:calculationLink link:definitionLink 2426402 - Disclosure - Income Taxes: Tax Benefit Related to Legal Restructuring (Details) link:presentationLink link:calculationLink link:definitionLink 2426403 - Disclosure - Income Taxes: TCJA (Details) link:presentationLink link:calculationLink link:definitionLink 2129100 - Disclosure - Leases: link:presentationLink link:calculationLink link:definitionLink 2429402 - Disclosure - Leases: Lessee (Details) link:presentationLink link:calculationLink link:definitionLink 2429407 - Disclosure - Leases: Lessee - Future Minimum Payments (Details) link:presentationLink link:calculationLink link:definitionLink 2429407 - Disclosure - Leases: Lessee - Future Minimum Payments (Details) link:presentationLink link:calculationLink link:definitionLink 2429403 - Disclosure - Leases: Lessee - Lease Costs (Details) link:presentationLink link:calculationLink link:definitionLink 2429404 - Disclosure - Leases: Lessee - Supplemental Balance Sheet Information (Details) link:presentationLink link:calculationLink link:definitionLink 2429405 - Disclosure - Leases: Lessee - Supplemental Cash Flow Information (Details) link:presentationLink link:calculationLink link:definitionLink 2429406 - Disclosure - Leases: Lessee - Weighted Average Information (Details) link:presentationLink link:calculationLink link:definitionLink 2429408 - Disclosure - Leases: Lessor (Details) link:presentationLink link:calculationLink link:definitionLink 2429409 - Disclosure - Leases: Lessor - Future Minimum Payments (Details) link:presentationLink link:calculationLink link:definitionLink 2329301 - Disclosure - Leases (Tables) link:presentationLink link:calculationLink link:definitionLink 2104100 - Disclosure - Management's Statement: link:presentationLink link:calculationLink link:definitionLink 2404402 - Disclosure - Management's Statement (Details) link:presentationLink link:calculationLink link:definitionLink 2204201 - Disclosure - Management's Statement (Policies) link:presentationLink link:calculationLink link:definitionLink 2110100 - Disclosure - Materials, Supplies and Fuel: link:presentationLink link:calculationLink link:definitionLink 2410402 - Disclosure - Materials, Supplies and Fuel (Details) link:presentationLink link:calculationLink link:definitionLink 2310301 - Disclosure - Materials, Supplies and Fuel (Tables) link:presentationLink link:calculationLink link:definitionLink 2114100 - Disclosure - Notes Payable, Current Maturities and Debt: link:presentationLink link:calculationLink link:definitionLink 2414403 - Disclosure - Notes Payable, Current Maturities and Debt: Debt Covenants (Details) link:presentationLink link:calculationLink link:definitionLink 2414402 - Disclosure - Notes Payable, Current Maturities and Debt: Schedule of Short-term Debt and Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2314301 - Disclosure - Notes Payable, Current Maturities and Debt (Tables) link:presentationLink link:calculationLink link:definitionLink 2120100 - Disclosure - Other Comprehensive Income (Loss): link:presentationLink link:calculationLink link:definitionLink 2420403 - Disclosure - Other Comprehensive Income (Loss): Accumulated Other Comprehensive Income (Details) link:presentationLink link:calculationLink link:definitionLink 2420402 - Disclosure - Other Comprehensive Income (Loss): Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) link:presentationLink link:calculationLink link:definitionLink 2320301 - Disclosure - Other Comprehensive Income (Loss) (Tables) link:presentationLink link:calculationLink link:definitionLink 2108100 - Disclosure - Regulatory Accounting: link:presentationLink link:calculationLink link:definitionLink 2408402 - Disclosure - Regulatory Accounting (Details) link:presentationLink link:calculationLink link:definitionLink 2408403 - Disclosure - Regulatory Accounting: Rate Review (Details) link:presentationLink link:calculationLink link:definitionLink 2308301 - Disclosure - Regulatory Accounting (Tables) link:presentationLink link:calculationLink link:definitionLink 2105100 - Disclosure - Revenue: link:presentationLink link:calculationLink link:definitionLink 2405402 - Disclosure - Revenue: Disaggregation of Revenue (Details) link:presentationLink link:calculationLink link:definitionLink 2305301 - Disclosure - Revenue (Tables) link:presentationLink link:calculationLink link:definitionLink 2116100 - Disclosure - Risk Management Activities: link:presentationLink link:calculationLink link:definitionLink 2416403 - Disclosure - Risk Management Activities: Cash Flow Hedges (Details) link:presentationLink link:calculationLink link:definitionLink 2416404 - Disclosure - Risk Management Activities: Derivatives Not Designated as Hedge Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 2316301 - Disclosure - Risk Management Activities (Tables) link:presentationLink link:calculationLink link:definitionLink 2416402 - Disclosure - Risk Management Activities: Utilities (Details) link:presentationLink link:calculationLink link:definitionLink 2121100 - Disclosure - Supplemental Disclosure of Cash Flow Information: link:presentationLink link:calculationLink link:definitionLink 2421402 - Disclosure - Supplemental Disclosure of Cash Flow Information (Details) link:presentationLink link:calculationLink link:definitionLink 2321301 - Disclosure - Supplemental Disclosure of Cash Flow Information (Tables) link:presentationLink link:calculationLink link:definitionLink