Consolidated Balance Sheets [Abstract] Consolidated Balance Sheets [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] Current assets: Assets, Current [Abstract] Cash and cash equivalents ($228 and $285 attributable to VIEs) Cash and Cash Equivalents, at Carrying Value Accounts receivable, net of allowance of $10 and $13 Accounts Receivable, Net, Current Margin deposits and other prepaid expense Margin deposits and other prepaid expenses Fair values as of the balance sheet date for all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments and which are expected to be converted into cash or otherwise disposed of greater than a year, presented gross of the effect of master netting agreements. Restricted cash, current ($92 and $57 attributable to VIEs) Restricted Cash and Cash Equivalents, Current Derivative Assets, Current Derivative Assets, Current Inventory and other current assets Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net ($4,535 and $4,313 attributable to VIEs) Property, Plant and Equipment, Net Restricted cash, net of current portion ($62 and $53 attributable to VIEs) Restricted Cash and Cash Equivalents, Noncurrent Investments Equity Method Investments Derivative Assets, Noncurrent Derivative Assets, Noncurrent Other assets Other Assets, Noncurrent Total assets Assets LIABILITIES & STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued interest payable ($47 and $19 attributable to VIEs) Interest Payable, Current Debt, current portion ($40 and $41 attributable to VIEs) Debt, Current Derivative liabilities, current Derivative Liabilities, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Debt, net of current portion ($2,819 and $2,522 attributable to VIEs) Long-term Debt, Excluding Current Maturities Derivative Liabilities, Noncurrent Derivative Liabilities, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (see Note 11) Commitments and Contingencies Stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Preferred stock, $0.001 par value per share; authorized 100,000,000 shares, none issued and outstanding Preferred Stock, Value, Issued Common stock, $0.001 par value per share; authorized 1,400,000,000 shares, 492,072,137 and 490,468,815 shares issued, respectively, and 465,572,396 and 481,743,738 shares outstanding, respectively Common Stock, Value, Issued Treasury stock, at cost, 26,499,741 and 8,725,077 shares, respectively Treasury Stock, Value Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Calpine stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and stockholders’ equity Liabilities and Equity Use of Collateral [Abstract] Use of Collateral Abstract Schedule of Collateral Collateral [Table Text Block] Collateral table text block Consolidated Statements of Cash Flows [Abstract] Consolidated Statements of Cash Flows [Abstract] Cash paid during the period for: Supplemental Cash Flow Information [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization expense Depreciation, Depletion and Amortization Debt extinguishment costs Non-Cash Gains Losses On Extinguishment Of Debt -- None. No documentation exists for this element. -- Deferred income taxes Increase (Decrease) in Deferred Income Taxes (Gain) loss on sale of power plants and other, net Gain (Loss) on Sale of Other Assets Unrealized mark-to-market activities, net Unrealized Gain (Loss) on Derivatives (Income) loss from unconsolidated investments in power projects Income (Loss) from Equity Method Investments Return on investment in unconsolidated subsidiaries Proceeds from Equity Method Investment, Dividends or Distributions Stock-based compensation expense Share-based Compensation Other Other Noncash Income (Expense) Change in operating assets and liabilities, net of effects of acquisitions: Increase (Decrease) in Operating Assets [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Derivative instruments, net Increase (Decrease) in Derivative Assets and Liabilities Other assets Increase (Decrease) in Other Operating Assets Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Settlement of non-hedging interest rate swaps Increase (Decrease) in Other Operating Liabilities Other liabilities Increase (Decrease) in Other Accounts Payable 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] Purchases of property, plant and equipment Property, Plant and Equipment, Additions Settlement of non-hedging interest rate swaps Payments for (Proceeds from) Derivative Instrument, Investing Activities Return of investment in unconsolidated investment in power plants Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital (Increase) decrease in restricted cash Increase (Decrease) in Restricted Cash Purchases of deferred transmission credits Payments to Acquire Intangible Assets Other Payments for (Proceeds from) Other Investing Activities Net cash 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] Repayment of Term Loans Repayment of Term Loans Repayment of Term Loans Borrowings under Term Loan and New Term Loan Funding of Term Loan Funding of Term Loan Repayments on NDH Project Debt Repayment on NDH Project Debt Repayments on NDH Project Debt Issuance of First Lien Notes Proceeds from Issuance of Senior Long-term Debt Repayments on First Lien Credit Facility Repayments of Debt Borrowings from project financing, notes payable and other Proceeds from Issuance of Long-term Debt Repayments of project financing, notes payable and other Repayments of Long-term Debt Capital contributions from noncontrolling interest holder Proceeds from Noncontrolling Interests Financing costs Payments of Financing Costs Stock repurchases Payments for Repurchase of Common Stock Other Proceeds from (Payments for) Other Financing Activities 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 Cash paid during the period for Cash paid during the period for Title for required cash payments as presented on the Statement of Cash Flows Interest, net of amounts capitalized Interest Paid, Net Income taxes Income Taxes Paid Supplemental disclosure of non-cash investing and financing activities: Noncash Investing and Financing Items [Abstract] Change in capital expenditures included in accounts payable Capital Expenditures Incurred but Not yet Paid Additions to property, plant and equipment through assumption of long-term note payable Notes Assumed Debt Disclosure [Abstract] Debt Disclosure [Text Block] Debt Disclosure [Text Block] Summary of Significant Accounting Policies [Abstract] Summary of Significant Accounting Policies [Abstract] Schedule of Property, Plant and Equipment [Table] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Table Text Block] Property, Plant and Equipment [Table Text Block] Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Components of Restricted Cash Schedule of Restricted Cash and Cash Equivalents [Table Text Block] Debt [Abstract] Debt [Abstract] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] First Lien Notes First Lien Notes [Table Text Block] First lien notes table text block Schedule of Line of Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Options, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Options, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Options, Outstanding, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options, Outstanding, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Options, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Options, Grants in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Options, Exercises in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Options, Exercises in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Options, Forfeitures in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Options, Forfeitures in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Options, Expirations in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Options, Expirations in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Options, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Options, Exercisable, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Options, Exercisable, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Options, Exercisable, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Options, Vested and Expected to Vest, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Fair Value Measurements [Abstract] Fair Value Measurements [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Minimum [Member] Minimum [Member] Physical Power [Member] Physical Power [Member] Physical Power [Member] Maximum [Member] Maximum [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Measurements, 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] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Margin deposits Derivative, Collateral, Right to Reclaim Cash Commodity futures contracts Commodity Futures Contracts Assets, Fair Value Disclosure Commodity Futures Contracts Assets, Fair Value Disclosure Commodity forward contracts Commodity Forward Contracts Assets, Fair Value Disclosure Commodity Forward Contracts Assets, Fair Value Disclosure Interest rate swaps Interest Rate Swap Assets, Fair Value Disclosure Interest Rate Swap Assets, Fair Value Disclosure Total assets Assets, Fair Value Disclosure Margin deposits held by us posted by our counterparties Derivative, Collateral, Obligation to Return Cash Commodity futures contracts Commodity Futures Contracts Liabilities, Fair Value Disclosure Commodity Futures Contracts Liabilities, Fair Value Disclosure Commodity forward contracts Commodity Forward Contracts Liabilities, Fair Value Disclosure Commodity Forward Contracts Liabilities, Fair Value Disclosure Interest rate swaps Interest Rate Swap Liabilities, Fair Value Disclosure Interest Rate Swap Liabilities, Fair Value Disclosure Fair Value Inputs Quantitative Information Power Fair Value Inputs Quantitative Information Power Fair Value Inputs Quantitative Information Power Liabilities, Fair Value Disclosure Liabilities, Fair Value Disclosure Assets and Liabilities with Recurring Fair Value Measurements Fair Value Disclosures [Text Block] Consolidated Statements of Comprehensive Income (Loss) [Abstract] Consolidated Statements of Comprehensive Income (Loss) [Abstract] Gain (loss) on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income (loss) Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Reclassification adjustment for (gain) loss on cash flow hedges realized in net income (loss) Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax Foreign currency translation gain (loss) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax Income tax (expense) benefit Other Comprehensive Income (Loss), Tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive (income) loss attributable to the noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income (loss) attributable to Calpine Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Inland Empire Energy Center [Member] Inland Empire Energy Center [Member] Inland Empire Energy Center member Equity Method Investee, Name [Axis] Equity Method Investee, Name [Domain] Greenfield [Member] Greenfield member Whitby [Member] Whitby member Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Power generation capacity Power generation capacity Power generation capacity Power generation capacity under construction Power generation capacity under construction Power generation capacity under construction Variable Interest Entity, Financial or Other Support, Amount Variable Interest Entity, Financial or Other Support, Amount Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Equity Method Investment, Summarized Financial Information, Debt Equity Method Investment, Summarized Financial Information, Debt Equity Method Investment, Summarized Financial Information, Debt Prorata Share of Equity Method Investment, Summarized Financial Information, Debt Prorata Share of Equity Method Investment, Summarized Financial Information, Debt Prorata Share of Equity Method Investment, Summarized Financial Information, Debt Equity Method Investment, Summarized Financial Information, Term Loan Period Equity Method Investment, Summarized Financial Information, Term Loan Period Equity Method Investment, Summarized Financial Information, Term Loan Period Equity Method Investment, Summarized Financial Information, Term Loan Equity Method Investment, Summarized Financial Information, Term Loan Equity Method Investment, Summarized Financial Information, Term Loan Project financing interest rate spread - Canadian LIBOR Project financing interest rate spread - Canadian LIBOR Project financing interest rate spread - Canadian LIBOR Project financing interest rate spread - Canadian Prime Rate Project financing interest rate spread - Canadian Prime Rate Project financing interest rate spread - Canadian Prime Rate Distribution from equity method investee Distribution from equity method investee Distribution from equity method investee Call Option Exercise Period Call Option Exercise Period Call Option Exercise Period Put Option Exercise Period Put Option Exercise Period Put Option Exercise Period Segment and Significant Customer Information [Abstract] Segment and Significant Customer Information [Abstract] Schedule of Financial Data for Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Income Tax Disclosure [Abstract] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Income Tax Expense (Benefit) Intraperiod Tax Allocation Schedule of Income Tax Expense (Benefit) Intraperiod Tax Allocation [Table Text Block] Schedule of Income Tax Expense Benefit Intraperiod Tax Allocation Table Text Block Use of Collateral Use of Collateral [Text Block] -- None. No documentation exists for this element. -- Variable Interest Entities and Unconsolidated Investments [Abstract] Variable Interest Entities and Unconsolidated Investments Abstract Schedule of Equity Method Investments [Line Items] Derivative Instruments [Abstract] Derivative Instruments [Abstract] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instrument Risk [Axis] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Derivative Contract Type [Domain] Interest Rate Swap [Member] Commodity Option [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Gains (Loss) Recognized in OCI (Effective Portion) Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Gain (Loss) Reclassified from AOCI into Income (EffectivePortion) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Gain (Loss) Reclassified from AOCI into Income (IneffectivePortion) Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] 2019 First Lien Term Loan [Member] 2019 First Lien Term Loan [Member] 2019 First Lien Term Loan [Member] First Lien Term Loans [Member] First Lien Term Loans [Member] First Lien Term Loans [Member] BRSP [Member] BRSP [Member] BRSP [Member] Russell City Project [Member] Russell City Project [Member] Russell City Project Member Los Esteros Project [Member] Los Esteros Project [Member] Los Esteros Project Member Corporate Revolving Facility [Member] Corporate Revolving Facility [Member] Corporate Revolving Facility Member CDHI [Member] CDHI [Member] CDHI [Member] First Lien Notes 2017 [Member] First Lien Notes 2017 [Member] 2017 First Lien Notes Member First Lien Notes 2019 [Member] First Lien Notes 2019 [Member] 2019 First Lien Notes Member Interest Periods [Axis] Interest Periods Axis Interest Periods [Domain] Interest Periods Domain One Month [Member] One Month Member Two Months [Member] Two Months Member Three Months [Member] Three Months Member Six Months [Member] Six Months Member Nine Months [Member] Nine Months Member Twelve Months [Member] Twelve Months Member Debt Instrument [Line Items] Debt Instrument [Line Items] Business Acquisition, Purchase Price Allocation, Assets Acquired Business Acquisition, Purchase Price Allocation, Assets Acquired Block one power generation capacity Block one power generation capacity Block one power generation capacity Redemption amount percentage Redemption amount percentage Redemption amount percentage Debt Instrument Redemption Premium Percentage Debt Instrument Redemption Premium Percentage Debt Instrument Redemption Premium Percentage Term loan interest rate spread option Federal Funds effective rate Term loan interest rate spread option Federal Funds effective rate Term loan interest rate spread option Prime Rate Term loan interest rate spread option Prime Rate Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum Percentage of principal amount of Term Loan to be paid quarterly Percentage of the principal amount of the Term Loan to be paid quarterly Percentage of Term Loan amounts held by lenders Percentage of Term Loan amounts held by lenders Debt Instrument, Face Amount Debt Instrument, Face Amount Gains (Losses) on Extinguishment of Debt Gains (Losses) on Extinguishment of Debt Power generation capacity after upgrade Power generation capacity after upgrade Power generation capacity after upgrade Long-term Construction Loan, Noncurrent Long-term Construction Loan, Noncurrent Project Letter of Credit Facility Project Letter of Credit Facility Project Letter of Credit Facility Term Loan Period Term Loan Period Term Loan Period Debt Service Letter of Credit Facility Debt Service Letter of Credit Facility Debt Service Letter of Credit Facility Amount Drawn Under Construction Loan Amount Drawn Under Construction Loan Amount Drawn Under Construction Loan Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Upsize Facility Total Upsize Facility Total Upsize Facility Total Applicable margin range percentage above base rate Applicable margin range percentage above base rate Applicable margin range percentage above base rate Percentage added to Federal Funds Effective Rate to arrive at base rate Percentage added to Federal Funds Effective Rate to arrive at base rate Percentage added to Federal Funds Effective Rate to arrive at base rate Interest periods for LIBOR rate borrowings Interest periods for LIBOR rate borrowings Interest periods for LIBOR rate borrowings Applicable Margin Range Percentage Above British Bankers' Association Interest Settlement Rates Applicable Margin Range Percentage Above British Bankers' Association Interest Settlement Rates Applicable margin range percentage added to the British Bankers' Association Interest Settlement Rates Repayment time for drawings under letters of credit Repayment time for drawings under letters of credit Unused commitment fee range percentage Unused commitment fee range percentage Unused commitment fee range percentage Excess amount of asset sales requiring mandatory prepayments Excess amount of asset sales requiring mandatory prepayments Excess amount of asset sales requiring mandatory prepayments Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Block two power generation capacity Block two power generation capacity Block two power generation capacity Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Equity Method Investee, Name [Axis] Equity Method Investee, Name [Domain] Greenfield [Member] Whitby [Member] (Income) loss from unconsolidated investments in power plants Acquisitions and Divestitures [Abstract] Acquisitions and Divestitures [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Broad River Energy Center [Member] Broad River Energy Center [Member] [Domain] Broad River Energy Center [Member] [Domain] Business Acquisition [Line Items] Business Acquisition [Line Items] Proceeds from Sale of Productive Assets Proceeds from Sale of Productive Assets Ownership percentage before divestiture of business Ownership percentage before divestiture of business Ownership percentage before divestiture of business Riverside Energy Center [Member] Riverside Energy Center [Member] Riverside Energy Center [Member] Assets Liabilities Working capital Working capital Working capital Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Realized Unrealized Gain Loss by Instrument Realized Unrealized Gain Loss by Instrument [Table Text Block] Realized Unrealized Gain Loss by Instrument Table Text Block Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Derivatives Designated as Hedges Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block] Acquisition of Bosque [Table] Acquisition of Bosque [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Bosque Energy Center [Member] Bosque Energy Center [Member] Bosque Energy Center [Member] Schedule of Non-Qualified Stock Option Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Assumptions Used to Estimate Fair Value for Options Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Restricted Stock and Restricted Stock Unit Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Earnings (Loss) per Share [Abstract] Earnings (Loss) per Share [Abstract] Earnings (Loss) per Share Earnings Per Share [Text Block] U.S. Income (Loss) from Continuing Operations before Income Taxes, Domestic International Income (Loss) from Continuing Operations before Income Taxes, Foreign Total Income (loss) before income taxes and discontinued operations with noncontrolling interest Income (loss) before income taxes and discontinued operations with noncontrolling interest Operating Loss Carryforwards Available To Offset Future Income Operating Loss Carryforwards One time tax benefit from consolidation One time tax benefit from consolidation One time tax benefit from consolidation Income tax expense (benefit) Income Tax Expense (Benefit) Effective Income Tax Rate, Continuing Operations Effective Income Tax Rate, Continuing Operations Income Tax Expense (Benefit), Intraperiod Tax Allocation Income Tax Expense (Benefit), Intraperiod Tax Allocation Other Comprehensive Income (Loss), Tax State and foreign tax expense benefit State and foreign tax expense benefit State and foreign tax expense benefit NOLs expected to expire unutilized related to pre-emergence date NOLs NOLs expected to expire unutilized NOLs expected to expire unutilized related to pre-emergence date NOLs NOLs expected to expire unutilized due to carryforward time constraints NOLs expected to expire unutilized due to carryforward time constraints NOLs expected to expire unutilized due to carryforward time constraints Percent Decline In Market Cap Required To Trigger Transfer Restrictions Percent Decline In Market Cap Required To Trigger Transfer Restrictions Percent Decline In Market Cap Required To Trigger Transfer Restrictions Emergence Date Capitalization Emergence Date Capitalization Emergence Date Capitalization Percent Change in Ownership Required To Trigger Transfer Restrictions Percent Change in Ownership Required To Trigger Transfer Restrictions Percent Change in Ownership Required To Trigger Transfer Restrictions Holders with ownership that could be affected by transfer restrictions Holders with ownership that could be affected by transfer restrictions Holders with ownership that could be affected by transfer restrictions Unrecognized Tax Benefits Unrecognized Tax Benefits Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits Resulting in Net Operating Loss Carryforward Unrecognized Tax Benefits Resulting in Net Operating Loss Carryforward Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound Tax refund due to foreign dividend income treatment Tax refund due to foreign dividend income treatment Tax refund due to foreign dividend income treatment Tax refund plus accrued interest due to foreign dividend income treatment Tax refund plus accrued interest due to foreign dividend income treatment Tax refund plus accrued interest due to foreign dividend income treatment Accrued interest on foreign dividend refund Accrued interest on foreign dividend refund Accrued interest on foreign dividend refund Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Current derivative assets Derivative Instruments and Hedges, Assets Long-term derivative assets Derivative Instruments and Hedges, Noncurrent Total derivative assets Derivative Asset, Fair Value, Gross Asset Current derivative liabilities Derivative Liabilities, Noncurrent Total derivative liabilities Derivative Liability, Fair Value, Gross Asset Net derivative assets (liabilities) Derivative, Fair Value, Net Fair Value of Derivative Assets Derivative Asset, Fair Value, Net Fair Value of Derivative Liabilities Derivative Liability, Fair Value, Net Summary of Significant Accounting Policies [Table] Summary of Significant Accounting Policies [Table] Summary of Significant Accounting Policies [Table] Two Development Projects [Member] Two Development Projects [Member] Two Development Projects [Member] Restricted Cash and Cash Equivalents [Axis] Restricted Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Debt Service Debt Service [Member] Debt service member Rent Reserve Rent Reserve [Member] Rent Reserve member Construction Major Maintenance Construction Major Maintenance [Member] Construction major maintenance member Security Project Insurance Security Project Insurance [Member] Security project insurance member Other Other Restricted Cash [Member] Other restricted cash member Restricted Cash and Cash Equivalents Items [Line Items] Current Non-current Total Restricted Cash and Cash Equivalents Basis Of Presentation and Summary of Significant Accounting Policies (Textuals) [Abstract] Basis Of Presentation and Summary of Significant Accounting Policies textuals abstract Cash and cash equivalents subject to project finance facilities and lease agreements Cash and cash equivalents subject to project finance facilities and lease agreements Held-to-maturity Securities, Restricted Held-to-maturity Securities, Restricted Interest Costs Capitalized Interest Costs Capitalized Inventory Inventory, Net Treasury Stock, Value, Acquired, Cost Method Treasury Stock, Value, Acquired, Cost Method Adjustments Related to Tax Withholding for Share-based Compensation Adjustments Related to Tax Withholding for Share-based Compensation Accounting Policies [Abstract] Accounting Policies [Abstract] Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Operating Leases, Future Minimum Payments Receivable Operating Leases, Future Minimum Payments Receivable Income Taxes Income Tax Disclosure [Text Block] Segment and Significant Customer Information Segment Reporting Disclosure [Text Block] Business Combinations [Abstract] Acquisitions and Divestitures Mergers, Acquisitions and Dispositions Disclosures [Text Block] Derivatives, Policy [Policy Text Block] Derivatives, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates, Policy [Policy Text Block] Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Inventory Inventory, Policy [Policy Text Block] Commitments and Contingencies, Policy [Policy Text Block] Commitments and Contingencies, Policy [Policy Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest Rate Swap [Member] Derivative Instruments (Textuals) [Abstract] Derivative Instruments Textuals Abstract Maximum Length of Power Purchase Agreements Maximum Length of Power Purchase Agreements Maximum Length of Power Purchase Agreements Maximum length of time hedging using commodity derivative instruments Maximum length of time hedging using commodity derivative instruments Maximum length of time hedging using commodity derivative instruments Maximum length of time hedging using interest rate derivative instruments Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge Derivative, Net Liability Position, Aggregate Fair Value Derivative, Net Liability Position, Aggregate Fair Value Collateral Already Posted, Aggregate Fair Value Collateral Already Posted, Aggregate Fair Value Additional Collateral, Aggregate Fair Value Additional Collateral, Aggregate Fair Value Early Repayment of Senior Debt Early Repayment of Senior Debt Notional Amount Interest Rate Derivative Underlying Debt Repaid During Period Notional Amount Interest Rate Derivative Underlying Debt Repaid During Period Notional Amount Interest Rate Derivative Underlying Debt Repaid During Period Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net Cumulative cash flow hedge losses remaining in AOCI Cumulative cash flow hedge losses remaining in AOCI Cumulative cash flow hedge losses remaining in AOCI Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Losses from interest rate contracts reclassified from OCI into earnings Losses from interest rate contracts reclassified from OCI into earnings Losses from interest rate contracts reclassified from OCI into earnings Notional Amount Interest Rate Derivative Underlying Debt Repaid Notional Amount Interest Rate Derivative Underlying Debt Repaid Notional Amount Interest Rate Derivative Underlying Debt Repaid Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments Interest Rate Derivative Liabilities, Fair Value on Settlement Date [Line Items] Interest Rate Derivative Liabilities, Fair Value on Settlement Date [Abstract] Interest Rate Derivative Liabilities, Fair Value on Settlement Date [Abstract] Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments, realized Gain Loss On Interest Rate Derivative Instruments Not Designated As Hedging Instruments, Realized GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsRealized Gain Loss On Interest Rate Derivative Instruments Not Designated As Hedging Instruments, Unrealized Gain Loss On Interest Rate Derivative Instruments Not Designated As Hedging Instruments, Unrealized Gain Loss On Interest Rate Derivative Instruments Not Designated As Hedging Instruments, Unrealized Natural gas and power prepayments Natural gas and power prepayments Natural gas and power prepayments Total margin deposits and natural gas and power prepayments with our counterparties Derivative Collateral Right To Reclaim Cash And Natural Gas And Power Prepayments Total Derivative Collateral Right To Reclaim Cash And Natural Gas And Power Prepayments Total Letters of credit issued Letters of credit issued Letters of credit issued First priority liens under power and natural gas agreements First priority liens under power and natural gas agreements First priority liens under power and natural gas agreements First priority liens under interest rate swap agreements First priority liens under interest rate swap agreements First priority liens under interest rate swap agreements Total letters of credit and first priority liens with our counterparties Letters of Credit Issued and First Priority Liens Under Power Natural Gas And Interest Rate Swap Agreements Letters of Credit Issued and First Priority Liens Under Power Natural Gas And Interest Rate Swap Agreements Letters of credit posted with us by our counterparties Letters Of Credit Posted By Counterparties Letters Of Credit Posted By Counterparties Total margin deposits and letters of credit posted with us by our counterparties Derivative Collateral Obligation To Return Cash And Letters Of Credit Posted By Counterparties Derivative Collateral Obligation To Return Cash And Letters Of Credit Posted By Counterparties Use of Collateral (Textuals) [Abstract] Use of Collateral Textuals Abstract Margin And Prepayment Amounts Included In Other Assets Margin And Prepayment Amounts Included In Other Assets Margin And Prepayment Amounts Included In Other Assets Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses Back-stopped amount of letters of credit used for commodity procurement and risk management activities Back-stopped amount of letters of credit used for commodity procurement and risk management activities Back-stopped amount of letters of credit used for commodity procurement and risk management activities Commodity Instruments Collateralized By First Priority Liens, Fair Value Commodity Instruments Collateralized By First Priority Liens, Fair Value Commodity Instruments Collateralized By First Priority Liens, Fair Value Line of Credit Facility [Table] Line of Credit Facility [Table] Lender Name [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] CDH [Member] CDH [Member] Calpine Development Holdings Member Various Project Financing Facilities [Member] Various Project Financing Facilities [Member] Various project financing facilities member Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entities [Table] Entities [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Basis of Presentation and Summary of Significant Accounting Principles [Abstract] Basis of Presentation and Summary of Significant Accounting Principles [Abstract] Buildings, machinery and equipment Buildings, Machinery and Equipment, Gross Buildings, machinery and equipment, gross Geothermal properties Geothermal Properties, Gross Geothermal Properties, Gross Other Property, Plant and Equipment, Other, Gross Property, Plant and Equipment, Gross Property, Plant and Equipment, Gross Less: Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, Plant and Equipment, Gross, Less Accumulated Depreciation Property, Plant and Equipment, Gross, Less Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment -- None. No documentation exists for this element. -- Land Land Construction in progress Construction in Progress, Gross Property, plant and equipment, net Price Risk Derivatives [Abstract] Power (MWh) Nonmonetary Notional Amount of Price Risk Derivatives Power Nonmonetary Notional Amount of Price Risk Derivatives Power Natural gas (MMBtu) Nonmonetary Notional Amount of Price Risk Derivatives Natural Gas Nonmonetary Notional Amount of Price Risk Derivatives Natural Gas Interest rate swaps Notional Amount of Interest Rate Derivatives Fair Value Inputs, Liabilities, Quantitative Information [Table] Fair Value Inputs, Liabilities, Quantitative Information [Table] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Fair Value Inputs, Liabilities, Quantitative Information [Table Text Block] Fair Value Inputs, Liabilities, Quantitative Information [Table Text Block] Fair Value, Measurement Inputs, Disclosure Fair Value, Measurement Inputs, Disclosure [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] Schedule of Weighted Average Number of Shares Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Variable Interest Entities and Unconsolidated Investments Variable Interest Entities and Unconsolidated Investments [Text Block] -- None. No documentation exists for this element. -- Asset Class [Axis] Asset Class [Axis] Fair Value by Asset Class [Domain] Fair Value by Asset Class [Domain] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance, beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Included in net income: Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Earnings [Abstract] Included in operating revenues Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Gain (Loss) Included in Operating Revenue Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Gain (Loss) Included in Operating Revenue Included in fuel and purchased energy expense Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Gain (Loss) Included In Fuel And Purchased Energy Expense Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Gain (Loss) Included In Fuel And Purchased Energy Expense Included in OCI Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Purchases, issuances and settlements: Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issues, Settlements [Abstract] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issues Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issues Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Transfers into level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Balance, end of period Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Change in Unrealized Gain (Loss) Held At Period End Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Change in Unrealized Gain (Loss) Held At Period End Fair Value, Assets Measured with Unobservable Inputs on Recurring Basis, Change in Unrealized Gain (Loss) Held At Period End Assets and Liabilities with Recurring Fair Value Measurements (Textuals) [Abstract] Assets and Liabilities with Recurring Fair Value Measurements Textuals Abstract Cash Equivalents Included In Cash And Cash Equivalents, Fair Value Disclosure Cash Equivalents Included In Cash And Cash Equivalents, Fair Value Disclosure Cash Equivalents Included In Restricted Cash, Fair Value Disclosure Cash Equivalents Included In Restricted Cash, Fair Value Disclosure Cash Equivalents Included In Restricted Cash, Fair Value Disclosure Schedule of Equity Method Investments Schedule of Equity Method Investments [Table Text Block] Income/Loss from Unconsolidated Investments in Power Plants and Distributions Income/loss from unconsolidated investments in power plants and Distributions [Table Text Block] Income/loss from unconsolidated investments in power plants and Distributions [Table Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Corporate Debt Securities [Member] Corporate Debt Securities [Member] Notes Payable and Other Payables excluding Leases [Member] Notes Payable and Other Payables excluding Leases [Member] Notes Payable and Other Payables excluding Leases [Member] Loans Payable [Member] Loans Payable [Member] Secured Debt [Member] Secured Debt [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Long-term Debt, Fair Value Long-term Debt, Fair Value Long-term Debt Long-term Debt Long Term Debt, Fair Value Excluding Capital Leases Long Term Debt, Fair Value Excluding Capital Leases Long Term Debt, Fair Value Excluding Capital Leases Debt Excluding Capital Leases Debt Excluding Capital Leases -- None. No documentation exists for this element. -- Notes Payable, Other Payables [Member] Notes Payable, Other Payables [Member] Capital Lease Obligations [Member] Capital Lease Obligations [Member] Debt, Current Long-term Debt, Excluding Current Maturities Share-based awards Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Shares Of New, Reorganized Common Stock Shares Of New, Reorganized Common Stock Shares Of New, Reorganized Common Stock Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic Weighted Average Number Diluted Shares Outstanding Adjustment Weighted Average Number Diluted Shares Outstanding Adjustment Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Summary of Derivative Instruments by Risk Exposure [Abstract] Power contracts included in operating revenues Power contracts included in operating revenues Power contracts included in operating revenues Natural gas contracts included in fuel and purchased energy expense Natural gas contracts included in fuel and purchased energy expense Natural gas contracts included in fuel and purchased energy expense Interest rate swaps included in interest expense Interest rate swaps included in interest expense Interest rate swaps included in interest expense Gain (Loss) on interest rate derivatives, net Gain (Loss) on Derivative Instruments, Net, Pretax Gain (Loss) on Derivative Instruments, Net, Pretax Gain (Loss) on Sale of Derivatives Gain (Loss) on Sale of Derivatives Unrealized gain (loss) First Lien Notes 2020 [Member] First Lien Notes 2020 [Member] 2020 First Lien Notes Member First Lien Notes 2021 [Member] First Lien Notes 2021 [Member] 2021 First Lien Notes Member First Lien Notes 2023 [Member] First Lien Notes 2023 [Member] 2023 First Lien Notes Member Balance Sheet Parentheticals [Abstract] Balance Sheet Parentheticals [Abstract] Cash and Cash Equivalents At Carrying Value Attributable to VIE Cash and Cash Equivalents At Carrying Value Attributable to VIE Cash and Cash Equivalents At Carrying Value Attributable to VIE Allowance for Doubtful Accounts Receivable, Current Allowance for Doubtful Accounts Receivable, Current Restricted Cash And Cash Equivalents At Carrying Value Attributable To Vie Restricted Cash And Cash Equivalents At Carrying Value Attributable To Vie Restricted Cash And Cash Equivalents At Carrying Value Attributable To Vie Property Plant And Equipment Net Attributable To Vie Property Plant And Equipment Net Attributable To Vie Property Plant And Equipment Net Attributable To Vie Restricted Cash And Cash Equivalents Noncurrent Attributable To Vie Restricted Cash And Cash Equivalents Noncurrent Attributable To Vie Restricted Cash And Cash Equivalents Noncurrent Attributable To Vie Accrued Interest Attributable To Vie Accrued Interest Attributable To Vie Accrued Interest Attributable To Vie Debt Current Attributable To Vie Debt Current Attributable To Vie Debt Current Attributable To Vie Long Term Debt Noncurrent Attributable To Vie Long Term Debt Noncurrent Attributable To Vie Long Term Debt Noncurrent Attributable To Vie Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Preferred Stock, Shares Issued Preferred Stock, Shares Issued Preferred Stock, Shares Outstanding Preferred Stock, Shares Outstanding Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Treasury Stock, Shares Treasury Stock, Shares Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Stock Options [Member] Restricted Stock [Member] Restricted Stock Units (RSUs) [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value Cash Received from Exercise of Stock Options Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options Fair Value of Restricted Stock That Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Expected Term Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Risk Free Interest Rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected Volatility Rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected Dividend Rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Nonvested Restricted Stock, Beginning balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Nonvested Restricted Stock, Beginning balance, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Grants in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Grants in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Forfeitures in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Forfeitures in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Vested in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Vested in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Nonvested Restricted Stock, Ending balance Nonvested Restricted Stock, Ending balance, Weighted Average Grant Date Fair Value Disclosure of Compensation Related Costs Share-based Payments (Textuals) [Abstract] Disclosure of Compensation Related Costs Share-based Payments Textuals Abstract Vesting period for graded and cliff vesting options - minimum Vesting period for graded and cliff vesting options - minimum Vesting period for graded and cliff vesting options - minimum Vesting period for graded and cliff vesting options - maximum Vesting period for graded and cliff vesting options - maximum Vesting period for graded and cliff vesting options - maximum Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Minimum Range Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Minimum Range Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Minimum Range Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Maximum Range Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Maximum Range Share-based Compensation Arrangement by Share-based Payment Award, Expiration Maximum Range Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Directors Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Directors Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Directors Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Employees Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Employees Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Employees Vest Term of First Sub Grant Vest Term of First Sub Grant Vesting Term of First Sub Grant Vest Term of the Second Sub-Grant Vest Term of the Second Sub-Grant Vesting Term of the Second Sub-Grant Percentage of sub-grants representing the total Percentage of sub-grants representing the total grant Vest Term of the Third Sub-Grant Vest Term of the Third Sub-Grant Vesting Term of the Third Sub-Grant Grants in Option Grants with Three Year Cliff Vesting Grants in Option Grants with Three Year Cliff Vesting Number of Grants in Option Grants with Three Year Cliff Vesting Vesting term of option grants with three year cliff vesting Vesting term of option grants with three year cliff vesting Vesting term of option grants with three year cliff vesting Income Statement [Abstract] Operating revenues Revenues Operating expenses: Cost of Revenue [Abstract] Fuel and purchased energy expense Cost of Revenue Plant operating expense Operating Costs and Expenses Depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Sales, general and other administrative expense Selling, General and Administrative Expense Other operating expense Other Cost and Expense, Operating Total operating expenses Costs and Expenses Income (loss) from operations Operating Income (Loss) Interest expense Interest Expense Loss on interest rate derivatives Interest (income) Investment Income, Interest Debt extinguishment costs Other (income) expense, net Other Nonoperating Income (Expense) Income (loss) before income taxes and discontinued operations Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Net income (loss) Net (income) loss attributable to the noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to Calpine Net Income (Loss) Attributable to Parent Basic earnings (loss) per common share attributable to Calpine: Earnings Per Share, Basic [Abstract] Weighted average number of shares outstanding, Basic Net income (loss) per common share attributable to Calpine - Basic Earnings Per Share, Basic Diluted earnings (loss) per common share attributable to Calpine: Earnings Per Share, Diluted [Abstract] Weighted average shares of common stock outstanding, Diluted (in thousands) Net income (loss) per common share attributable to Calpine — diluted Earnings Per Share, Diluted Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Major Customers [Axis] Major Customers [Axis] Name of Major Customer [Domain] Name of Major Customer [Domain] PJM Settlement, Inc. [Member] PJM Settlement, Inc. [Member] PJM Settlement, Inc. [Member] Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Segment, Geographical [Domain] West [Member] West Member Texas [Member] TEXAS North [Member] North Member Southeast [Member] Southeast Member Consolidation and Elimination [Member] Intersegment Elimination [Member] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from external customers Intersegment revenues Segment Reporting Information, Intersegment Revenue Total operating revenues Segment Reporting Information, Revenue for Reportable Segment Commodity Margin Commodity Margin Commodity Margin Add: Mark-to-market commodity activity, net and other Mark-to-Market Commodity Activity, Net and Other Revenue Mark-to-Market Commodity Activity, Net and Other Revenue Other operating expenses OtherCostandExpenseOperatingExcludingRGGIComplianceAndOtherEnvironmentalCosts OtherCostandExpenseOperatingExcludingRGGIComplianceAndOtherEnvironmentalCosts Impairment losses Other than Temporary Impairment Losses, Investments Gain (Loss) on Disposition of Assets Gain (Loss) on Disposition of Assets Interest expense, net of interest income Interest Revenue (Expense), Net Loss on interest rate derivatives Debt Extinguishment Costs and Other (Income) Expense, Net Debt Extinguishment Costs and Other (Income) Expense, Net Debt Extinguishment Costs and Other (Income) Expense, Net Lease levelization Lease levelization LeaseLevelization Contract amortization Contract amortization Contract amortization RGGI Compliance and Other Environmental Costs RGGI Compliance and Other Environmental Costs Regional Greenhouse Gas Initiative Compliance and Other Environmental Costs Major customer revenue Entity-Wide Revenue, Major Customer, Amount Major customer receivables Receivables, Major Customer, Amount Receivables, Major Customer, Amount Number of significant customers Number of Significant Customers Number of Significant Customers Commodity Margin Riverside Energy Center Commodity Margin Riverside Energy Center Commodity Margin including in our North Segment related to Riverside Energy Center Stock-Based Compensation Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]