v3.19.3.a.u2

Variable Interest Entities and Unconsolidated Investments (VIE Textuals) (Details) $ in Millions |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Jan. 01, 2020 USD ($) | Dec. 31, 2019 USD ($) yr MW | Dec. 31, 2019 USD ($) yr MW | Dec. 31, 2018 USD ($) MW | Dec. 31, 2017 USD ($) | Nov. 20, 2019
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Proceeds from sale of power plants and other | [1] |  |  | $ 322 | $ 11 | $ 162 |
Gain (Loss) on Disposition of Assets |  |  |  | 10 | 0 | $ 27 |
Equity Method Investment, Summarized Financial Information, Debt |  |  | $ 299 | 299 | 301 |  |
Prorata Share of Equity Method Investment, Summarized Financial Information, Debt |  |  | 150 | 150 | 151 |  |
Long-term Debt |  |  | $ 11,857 | 11,857 | $ 10,156 |  |
Put Option [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Proceeds from sale of power plants and other |  |  |  | 280 |  |  |
Call Option [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Proceeds from sale of power plants and other |  |  |  | $ 377 |  |  |
Russell City Energy [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Minority Interest Ownership Percentage By Noncontrolling Third Party Owners |  |  | 25.00% | 25.00% |  |  |
Equity Method Investment, Ownership Percentage |  |  | 75.00% | 75.00% |  |  |
Variable Interest Entity, Primary Beneficiary [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Power generation capacity | MW |  |  | 6,669 | 6,669 | 7,880 |  |
Inland Empire Energy Center [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Power generation capacity | MW |  |  | 775 | 775 |  |  |
Put Option Exercise Period | yr |  |  | 2,025 | 2,025 |  |  |
Minimum [Member] | Inland Empire Energy Center [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Call Option Exercise Period | yr |  |  | 2,017 | 2,017 |  |  |
Maximum [Member] | Inland Empire Energy Center [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Call Option Exercise Period | yr |  |  | 2,024 | 2,024 |  |  |
Calpine Receivables [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount |  |  | $ 48 | $ 48 |  |  |
Equity Method Investment, Ownership Percentage |  |  | 100.00% | 100.00% |  |  |
Greenfield [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Power generation capacity | MW |  |  | 1,038 | 1,038 |  |  |
Equity Method Investment, Ownership Percentage | [2] |  | 50.00% | 50.00% |  |  |
Whitby [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Power generation capacity | MW |  |  | 50 | 50 |  |  |
Equity Method Investment, Ownership Percentage | [3] |  | 0.00% | 0.00% |  |  |
Equity Method Investment Ownership Interest Sold |  |  |  |  |  |  | 50.00%
Gain (Loss) on Disposition of Assets |  |  | $ 5 |  |  |  |
OMEC [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Long-term Debt | [4] |  | $ 0 | $ 0 | $ 218 |  |
Subsequent Event [Member] | Russell City Energy [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Payments to Acquire Businesses, Net of Cash Acquired |  | $ 49 |  |  |  |  |
[1] | Dividends paid during the years ended December 31, 2019 and 2018, includes approximately $1 million and $20 million, respectively, in certain Merger-related costs incurred by CPN Management, our parent.
[2] | Includes our share of accumulated other comprehensive income/loss related to interest rate hedging instruments associated with our unconsolidated subsidiary Greenfield LP’s debt.
[3] | On November 20, 2019, we sold our 50% interest in Whitby to a third party and recorded a gain on sale of assets, net of approximately $5 million.
[4] | On August 14, 2019, we repaid the project debt associated with OMEC from a portion of the proceeds received from the issuance of our 2026 First Lien Term Loans (as discussed above), together with cash on hand.

X
- Definition Call Option Exercise Period + References No definition available. + Details
Name: | cpn_CallOptionExercisePeriod
Namespace Prefix: | cpn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Equity Method Investment Ownership Interest Sold + References No definition available. + Details
Name: | cpn_EquityMethodInvestmentOwnershipInterestSold
Namespace Prefix: | cpn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Equity Method Investment, Summarized Financial Information, Debt + References No definition available. + Details
Name: | cpn_EquityMethodInvestmentSummarizedFinancialInformationDebt
Namespace Prefix: | cpn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Minority Interest Ownership Percentage By Noncontrolling Third Party Owners + References No definition available. + Details
Name: | cpn_MinorityInterestOwnershipPercentageByNoncontrollingThirdPartyOwners
Namespace Prefix: | cpn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Power generation capacity + References No definition available. + Details
Name: | cpn_PowerGenerationCapacity
Namespace Prefix: | cpn_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Prorata Share of Equity Method Investment, Summarized Financial Information, Debt + References No definition available. + Details
Name: | cpn_ProrataShareOfEquityMethodInvestmentSummarizedFinancialInformationDebt
Namespace Prefix: | cpn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Put Option Exercise Period + References No definition available. + Details
Name: | cpn_PutOptionExercisePeriod
Namespace Prefix: | cpn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118582676&loc=d3e5747-111685 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=118582676&loc=d3e5728-111685 + Details
Name: | us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_PutOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_CallOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=cpn_RussellCityEnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=cpn_InlandEmpireEnergyCenterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=cpn_CalpineReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=cpn_GreenfieldMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=cpn_WhitbyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=cpn_OmecMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |