v2.4.1.9

Debt (Project Financing, Notes Payable and Others) (Details) (USD $)
In Millions, unless otherwise specified

Dec. 31, 2014

Dec. 31, 2013

Russell City Project [Member]

Debt Instrument [Line Items]

Long-term Debt

$ 591us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_RussellCityProjectMember

$ 593us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_RussellCityProjectMember

Debt Instrument, Interest Rate, Effective Percentage

6.20%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_RussellCityProjectMember

^[1]

4.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_RussellCityProjectMember

^[1]

Steamboat [Member]

Debt Instrument [Line Items]

Long-term Debt

407us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_SteamboatMember

418us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_SteamboatMember

Debt Instrument, Interest Rate, Effective Percentage

6.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_SteamboatMember

^[1]

6.80%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_SteamboatMember

^[1]

OMEC [Member]

Debt Instrument [Line Items]

Long-term Debt

325us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_OmecMember

335us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_OmecMember

Debt Instrument, Interest Rate, Effective Percentage

6.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_OmecMember

^[1]

6.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_OmecMember

^[1]

Los Esteros Project [Member]

Debt Instrument [Line Items]

Long-term Debt

275us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_LosEsterosProjectMember

305us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_LosEsterosProjectMember

Debt Instrument, Interest Rate, Effective Percentage

3.10%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_LosEsterosProjectMember

^[1]

3.40%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_LosEsterosProjectMember

^[1]

Pasadena [Member]

Debt Instrument [Line Items]

Long-term Debt

122us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_PasadenaMember

^[2]

135us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_PasadenaMember

^[2]

Debt Instrument, Interest Rate, Effective Percentage

8.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_PasadenaMember

^[1],[2]

8.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_PasadenaMember

^[1],[2]

Bethpage [Member]

Debt Instrument [Line Items]

Long-term Debt

82us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_BethpageMember

^[3]

88us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_BethpageMember

^[3]

Debt Instrument, Interest Rate, Effective Percentage

7.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_BethpageMember

^[1],[3]

7.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_BethpageMember

^[1],[3]

Gilroy note payable [Member]

Debt Instrument [Line Items]

Long-term Debt

0us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_GilroyNotePayableMember

15us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= cpn_GilroyNotePayableMember

Debt Instrument, Interest Rate, Effective Percentage

0.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_GilroyNotePayableMember

^[1]

11.20%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= cpn_GilroyNotePayableMember

^[1]

Other Debt Obligations [Member]

Debt Instrument [Line Items]

Long-term Debt

8us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_OtherDebtSecuritiesMember

12us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_OtherDebtSecuritiesMember

Debt Instrument, Interest Rate, Effective Percentage

0.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= us-gaap_OtherDebtSecuritiesMember

^[1]

0.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= us-gaap_OtherDebtSecuritiesMember

^[1]

Project Financing Total [Member]

Debt Instrument [Line Items]

Long-term Debt

$ 1,810us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_NotesPayableOtherPayablesMember

$ 1,901us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_NotesPayableOtherPayablesMember

[1]	Our weighted average interest rate calculation includes the amortization of deferred financing costs and debt discount or premium.
[2]	Represents a failed sale-leaseback transaction that is accounted for as financing transaction under U.S. GAAP.
[3]	Represents a weighted average of first and second lien loans for the weighted average effective interest rates.

X

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. 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/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-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



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-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://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20, 22

-Article 5



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cpn_BethpageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cpn_GilroyNotePayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cpn_LosEsterosProjectMember
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_DebtInstrumentAxis=cpn_PasadenaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cpn_RussellCityProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cpn_SteamboatMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: