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[Member] Forward Settling Trades [Member] Forward Settling Trades [Member] Agency RMBS [Member] Residential Mortgage Backed Securities [Member] Accrued Interest on Pledged Securities [Member] Accrued Interest on Pledged Securities [Member] Accrued Interest on Pledged Securities [Member] Cash [Member] Cash [Member] Schedule of Investments [Line Items] Schedule of Investments [Line Items] Pledged Assets Separately Reported, Pledged as Collateral to Counterparties, at Fair Value Pledged Assets Separately Reported, Pledged as Collateral to Counterparties, at Fair Value Pledged Assets Separately Reported, Pledged as Collateral to Counterparties, at Fair Value Derivative Liabilities [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivative Asset, Notional Amount Derivative Asset, Notional Amount Derivative, Notional Amount Derivative, Notional Amount US Treasury short position, notional amount Derivative, Collateral, Obligation to Return Cash Derivative Liability, Fair Value, Gross Liability Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Statement [Line Items] Statement [Line Items] Assets: Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Agency RMBS (including pledged assets of $10,377,167 and $9,287,317, respectively) Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value U.S. Treasury securities (including pledged assets of $0 and $1,046,934, respectively) Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value Receivable for securities sold and principal repayments Receivables 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liabilities Liabilities Stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] 7.75% Series A Cumulative Redeemable Preferred Stock, (3,000 shares issued and outstanding, respectively, $75,000 in aggregate liquidation preference) Preferred Stock, Value, Issued 7.50% Series B Cumulative Redeemable Preferred Stock, (8,000 shares issued and outstanding, respectively, $200,000 in aggregate liquidation preference) us-gaap_PreferredStockValue_SeriesB us-gaap_PreferredStockValue_SeriesB Common Stock, $0.01 par value, 500,000 shares authorized (155,416 and 155,010 shares issued and outstanding, respectively) Common Stock, Value, Issued Additional paid in capital Additional Paid in Capital Retained earnings (accumulated deficit) Retained Earnings (Accumulated Deficit) Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders' equity Liabilities and Equity Real Estate Investments, Net Real Estate Investments, Net unobservable input capitalization rate min unobservable input capitalization rate min unobservable input capitalization rate min unobservable input capitalization rate max unobservable input capitalization rate max unobservable input capitalization rate max Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Net income (loss) Net Income (Loss) Attributable to Parent Less dividends on preferred shares Preferred Stock Dividends, Income Statement Impact Net income (loss) available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Common shares Dividends, Common Stock Non-vested shares Dividends, Share-based Compensation Undistributed earnings (loss) Undistributed Earnings, Basic Common shares Weighted Average Number of Shares Outstanding, Basic Distributed earnings Earnings Per Share, Basic, Distributed Undistributed earnings (loss) Earnings Per Share, Basic, Undistributed Basic earnings (loss) per common share Earnings Per Share, Basic Net effect of dilutive warrants (1) Weighted Average Number Diluted Shares Outstanding Adjustment Diluted weighted average shares outstanding Weighted Average Number of Shares Outstanding, Diluted Distributed earnings Earnings Per Share, Diluted, Distributed Undistributed earnings Earnings Per Share, Diluted, Undistributed Diluted earnings (loss) per common share Earnings Per Share, Diluted Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Banking and Thrift [Abstract] Repurchase Agreements Repurchase Agreements, Resale Agreements, Securities Borrowed, and Securities Loaned Disclosure [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Long [Member] Long [Member] Short [Member] Short [Member] Derivative Contract Type [Domain] Interest Rate Swap, Swaption, and Cap, March 2018 [Member] Interest Rate Swap, Swaption, and Cap, March 2018 [Member] Interest Rate Swap, Swaption, and Cap, March 2018 [Member] Interest Rate Swap and Cap, February 2018 [Member] Interest Rate Swap, Swaption and Cap, February 2018 [Member] Interest Rate Swap, Swaption, and Cap, February 2018 [Member] Interest Rate Cap [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative Instruments, Gain (Loss) [Table Text Block] Derivative, Notional Amount Derivative Asset, Fair Value, Gross Asset U.S. Treasury short position, notional amount US Treasury short position, notional amount US Treasury short position, notional amount Derivative and other hedging instruments, liabilities, notional Derivative Liability, Notional Amount Derivative Liability, Fair Value, Gross Liability Derivative, Average Notional Amount Derivative, Average Notional Amount Derivative, Average Notional Amount SwapandCapNotional SwapandCapNotional SwapandCapNotional Net realized and unrealized gain (loss) on swap, swaption and cap contracts TBA Derivatives, Realized and Unrealized Gain (loss), net Interest rate hedge expense, net Stockholders' Equity Note [Abstract] EquityTransactions [Table] EquityTransactions [Table] EquityTransactions [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Dividend Reinvestment And Direct Stock Purchase Plan [Member] Dividend Reinvestment And Direct Stock Purchase Plan [Member] Dividend Reinvestment And Direct Stock Purchase Plan [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] July 2014 Repurchase Plan [Member] July 2014 Repurchase Plan [Member] July 2014 Repurchase Plan [Member] Equity Issuance [Line Items] equity issuance [Line Items] equity issuance [Line Items] Common stock, shares authorized Common Stock, Shares Authorized Common stock, par value Common Stock, Par or Stated Value Per Share Common Stock, Shares, Issued Common Stock, Shares, Issued Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Preferred Stock, Shares Outstanding Preferred Stock, Shares Outstanding Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Preferred Stock, 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rate cap contracts Amortization Net realized (gain) loss on investments Gain (Loss) on Investments, Excluding Other than Temporary Impairments Net realized (gain) loss on termination of cap and swaption contracts Derivative, Gain on Derivative Net unrealized (gain) loss on investments Unrealized Gain (Loss) on Investments Net unrealized (gain) loss on derivative instruments Unrealized Gain (Loss) on Derivatives and Commodity Contracts Change in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Other assets Increase (Decrease) in Other Operating Assets Accrued interest payable Increase (Decrease) in Interest Payable, Net Accrued expenses and other liabilities Increase (Decrease) in Other Accrued Liabilities Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchase of available-for-sale investment securities Payments to Acquire Available-for-sale Securities Premium paid on interest rate caps and swaptions Premium paid on interest rate caps and swaptions Premium paid on interest rate caps and swaptions Proceeds from sale of available-for-sale investment securities Proceeds from Sale of Available-for-sale Securities Proceeds from sale of other investments Proceeds from Sale and Maturity of Other Investments Proceeds from Derivative Instrument, Financing Activities Proceeds from Derivative Instrument, Financing Activities Proceeds from paydowns of available-for-sale investment securities Proceeds from Maturities, Repayments and Calls of Trading Securities Held-for-investment Proceeds from Securities Purchased under Agreements to Resell Proceeds from Securities Purchased under Agreements to Resell Proceeds from (Payments for) Securities Purchased under Agreements to Resell Proceeds from (Payments for) Securities Purchased under Agreements to Resell Proceeds from U.S. Treasury short positions proceeds from US Treasury short positions proceeds from US Treasury short positions Change in assets and liabilities: Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract] Receivable for securities sold and principal repayments Increase (Decrease) in Receivables from Brokers-Dealers and Clearing Organizations Receivable for cash pledged as collateral Increase (Decrease) in Cash Collateral for Borrowed Securities Payable for securities purchased Increase (Decrease) in Payables to Broker-Dealers and Clearing Organizations Payable for cash received as collateral Increase (Decrease) Cash Collateral from Counterparties Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from repurchase agreements Proceeds from (Payments for) in Securities Sold under Agreements to Repurchase Repayments of repurchase agreements Repayments of Other Short-term Debt Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock Net payments for repurchase of common shares Dividends paid Payments of Dividends Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents - Beginning of period Cash and cash equivalents - End of period Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Interest paid (excluding interest paid on interest rate hedges) Interest Paid Net interest paid (received) on interest rate hedges InterestPaidNetInterestRateDerivative InterestPaidNetInterestRateDerivative Income taxes paid Income Taxes Paid Supplemental disclosures of non-cash flow information: Cash Flow, Noncash 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investments Unrealized Gain (Loss) on Securities Other income Other Income Net realized and unrealized gain (loss) on investments and other income Noninterest Income, Other Operating Income Before Gains (Losses) and Interest from Derivatives Noninterest Income, Other Operating Income Before Gains (Losses) and Interest from Derivatives Interest rate hedge expense, net Net realized and unrealized gain (loss) on derivative instruments Gain (Loss) on Sale of Derivatives Net gain (loss) on derivative instruments Net Gain (Loss) from Derivatives Net Gain (Loss) from Derivatives Total other income (loss) Noninterest Income (Expense) Noninterest Income (Expense) Expenses: Operating Costs and Expenses [Abstract] Compensation and benefits Labor and Related Expense General, administrative and other General and Administrative Expense Total expenses Costs and Expenses Net income (loss) Net income (loss) per common share basic & diluted Earnings Per Share, Basic and Diluted Dividends declared per 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Redeemable Preferred Stock, liquidation preference per share Common stock, shares authorized Common stock, shares issued Common stock, shares outstanding Common Stock, Shares, Outstanding Derivative Liability, Fair Value of Collateral Derivative Liability, Fair Value of Collateral Derivative Liability, Fair Value, Amount Offset Against Collateral Derivative Liability, Fair Value, Amount Offset Against Collateral RepurchaseagreementsandFederalHomeLoanBankAdvances RepurchaseagreementsandFederalHomeLoanBankAdvances RepurchaseagreementsandFederalHomeLoanBankAdvances Securities Sold under Agreements to Repurchase, Not Offset, Policy Election Deduction Securities Sold under Agreements to Repurchase and FHLBC Advances, Not Offset, Policy Election Deduction Securities Sold under Agreements to Repurchase and FHLBC Advances, Not Offset, Policy Election Deduction Securities Sold under Agreements to Repurchase, Right to Reclaim Securities and Cash Securities Sold under Agreements to Repurchase and FHLBC Advances, Right to Reclaim Securities and Cash Securities Sold under Agreements to Repurchase and FHLBC Advances, Right to Reclaim Securities and Cash Securities Sold under Agreements to Repurchase, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Securities Sold under Agreements to Repurchase and FHLBC Advances, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Securities Sold under Agreements to Repurchase and FHLBC Advances, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election InstrumentsAvailableToOffsetDerivativeLiability InstrumentsAvailableToOffsetDerivativeLiability InstrumentsAvailableToOffsetDerivativeLiability Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Unrealized loss on 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Pledged Assets Separately Reported, Pledged as Collateral from Counterparties, at Fair Value Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Prospective Adoption of New Accounting Pronouncements Schedule of Prospective Adoption of New Accounting Pronouncements [Table Text Block] Pledged Assets Transfers and Servicing of Financial Assets [Text Block] Schedule of Repurchase Agreement Counterparty [Table] Schedule of Repurchase Agreement Counterparty [Table] Repurchase Agreement Counterparty [Line Items] Repurchase Agreement Counterparty [Line Items] Schedule Of Computation Of Basic And Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Outstanding repurchase agreements Interest accrued thereon Accrued Interest Payable Including Accrued Interest On Repurchase Agreement Accrued interest payable including accrued interest on repurchase agreement. Weighted average borrowing rate Short-term Debt, Weighted Average Interest Rate Weighted-average remaining maturity (in days) Weighted Average Remaining Maturity (In Days) Weighted average remaining maturity (in days) Fair value of pledged collateral(1) Securities Sold under Agreements to Repurchase, Fair Value of Collateral Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets repurchase agreement Amount at Risk repurchase agreement Amount at Risk Number Of Repurchase Agreements exceeding 10% of Stockholders' Equity Number Of Repurchase Agreements Number of repurchase agreements Leases [Abstract] Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Lessee Leasing Arrangements, Operating Leases, Term of Contract RemainingLeaseTerm RemainingLeaseTerm Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments Due Operating Leases, Future Minimum Payments Due Basis Of Presentation Basis Of Presentation [Policy Text Block] Basis of presentation [Policy Text Block] Reclassification Reclassification, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Investments in Securities Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block] Agency RMBS Agency Residential Mortgage-Backed Securities [Policy Text Block] Agency residential mortgage-backed securities [Policy Text Block] Forward Settling Transactions Forward Settling Transactions [Policy Text Block] Forward Settling Transactions [policy text block] Investment Valuation Investment, Policy [Policy Text Block] Fair Value Measurement, Policy [Policy Text Block] Fair Value Measurement, Policy [Policy Text Block] Interest Income Investment Transactions And Income [Policy Text Block] Investment Transactions and Income [policy text block] Other investments Other investments [Policy Text Block] Other investments [Policy Text Block] Repurchase Agreements and FHLBC Advances Repurchase Agreements, Valuation, Policy [Policy Text Block] Repurchase Agreements, Resale Agreements, Securities Borrowed, and Securities Loaned Disclosure [Text Block] Derivative Instruments Derivatives, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Leases Lease, Policy [Policy Text Block] Stock-based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] RemainingLeaseTerm Indemnification claims Indemnification Claims Indemnification claims Assets Pledged to Counterparties Assets Pledged to Counterparties [Table Text Block] Assets Pledged to Counterparties [Table Text Block] Assets Pledged from Counterparties Assets Pledged from Counterparties [Table Text Block] Assets Pledged from Counterparties [Table Text Block] Offsetting Assets Offsetting Assets [Table Text Block] Offsetting Liabilities Offsetting Liabilities [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Preferred Stock, Liquidation Preference Per Share Fair Value Measurements Fair Value Disclosures [Text Block] Earnings Per Share Earnings Per Share [Text Block] Consolidated Statement Of Changes In Net Assets [Abstract] Consolidated Statement Of Changes In Net Assets [Abstract] Series A Preferred Stock Series A Preferred Stock [Member] Series B Preferred Stock us-gaap_PreferredStockValue_SeriesB [Member] us-gaap_PreferredStockValue_SeriesB [Member] Common Stock Par Value Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Balance Net income (loss) Issuance of common stock Amortization of share-based compensation Stock Issued During Period, Value, Share-based Compensation, Gross Repurchase and cancellation of common stock Stock Repurchased During Period, Value Preferred dividends Common dividends Dividends, Common Stock, Cash Balance Offsetting Assets [Table] Offsetting Assets [Table] Offsetting Assets [Line Items] Offsetting Assets [Line Items] InstrumentsAvailableToOffsetDerivativeAsset InstrumentsAvailableToOffsetDerivativeAsset InstrumentsAvailableToOffsetDerivativeAsset Derivative Asset, Fair Value of Collateral Derivative Asset, Fair Value of Collateral Derivative Asset, Fair Value, Amount Offset Against Collateral Derivative Asset, Fair Value, Amount Offset Against Collateral Receivable Under Reverse Repurchase Agreements cys_InstrumentsAvailableToOffsetReverseRepurchaseAgreements cys_InstrumentsAvailableToOffsetReverseRepurchaseAgreements cys_InstrumentsAvailableToOffsetReverseRepurchaseAgreements CollateralReceivedReverseRepurchaseAgreementSubjecttoMasterNetting CollateralReceivedReverseRepurchaseAgreementSubjecttoMasterNetting CollateralReceivedReverseRepurchaseAgreementSubjecttoMasterNetting NetAmountNotOffsetUnderReverseRepurchaseAgreements NetAmountNotOffsetUnderReverseRepurchaseAgreements NetAmountNotOffsetUnderReverseRepurchaseAgreements Receivable for reverse repurchase agreements Fair Value of Securities Received as Collateral that Have Been Resold or Repledged Derivative Asset, Fair Value, Amount Offset Against Collateral Schedule Of Company's Borrowings Schedule of Short-term Debt [Table Text Block] Schedule of Repurchase Agreements Schedule of Repurchase Agreements [Table Text Block] Trading Securities Pledged as Collateral Trading Securities Pledged as Collateral Derivative, Collateral, Right to Reclaim Cash Securities Received as Collateral Securities Received as Collateral Derivative, Collateral, Obligation to Return Cash Average notional on TBA derivatives Average notional on TBA derivatives Average notional on TBA derivatives SwapandCapNotionalasPercentageofRepoBorrowings SwapandCapNotionalasPercentageofRepoBorrowings SwapandCapNotionalasPercentageofRepoBorrowings U.S. Treasury short position, notional amount Subsequent Events Subsequent Events [Text Block] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Maturity Overnight [Member] Maturity Overnight [Member] Up to 30 days [Member] Maturity Less than 30 Days [Member] 30-90 days [Member] Maturity 30 to 90 Days [Member] Greater than 90 days [Member] Maturity Greater than 90 Days [Member] Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Total remaining contractual maturity of repo borrowings Securities Borrowed, Gross Including Not Subject to Master Netting Arrangement Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Beginning balance Level 3 assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Change in net unrealized gain (loss) Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Gross purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances Gross sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Net gain (loss) on sales Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings Transfers into (out of) level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Ending balance Level 3 assets Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Fair Value Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract] Less than one year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Greater than one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Greater than five years through ten years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Greater than ten years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Total Available-for-sale Securities, Debt Maturities, Single Maturity Date Amortized Cost Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturity [Abstract] Less than one year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Greater than one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Greater than five years through ten years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Greater than ten years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Total Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis