v2.4.0.6

Derivative Instruments (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2013
Derivative Instruments [Abstract] |
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] | The following tables present the fair values of our net derivative instruments recorded on our Consolidated Condensed Balance Sheets by location and hedge type at March 31, 2013 and December 31, 2012 (in millions):
| March 31, 2013
| Commodity Instruments |  | Interest Rate Swaps |  | Total Derivative Instruments
Balance Sheet Presentation |  |  |  |  |
Current derivative assets | $ | 514 |  |  | $ | — |  |  | $ | 514 |
Long-term derivative assets | 144 |  |  | 5 |  |  | 149 |
Total derivative assets | $ | 658 |  |  | $ | 5 |  |  | $ | 663 |
Current derivative liabilities | $ | 551 |  |  | $ | 44 |  |  | $ | 595 |
Long-term derivative liabilities | 145 |  |  | 144 |  |  | 289 |
Total derivative liabilities | $ | 696 |  |  | $ | 188 |  |  | $ | 884 |
Net derivative liabilities | $ | (38 | ) |  | $ | (183 | ) |  | $ | (221 | )
| December 31, 2012
| Commodity Instruments |  | Interest Rate Swaps |  | Total Derivative Instruments
Balance Sheet Presentation |  |  |  |  |
Current derivative assets | $ | 339 |  |  | $ | — |  |  | $ | 339 |
Long-term derivative assets | 94 |  |  | 4 |  |  | 98 |
Total derivative assets | $ | 433 |  |  | $ | 4 |  |  | $ | 437 |
Current derivative liabilities | $ | 317 |  |  | $ | 40 |  |  | $ | 357 |
Long-term derivative liabilities | 133 |  |  | 160 |  |  | 293 |
Total derivative liabilities | $ | 450 |  |  | $ | 200 |  |  | $ | 650 |
Net derivative liabilities | $ | (17 | ) |  | $ | (196 | ) |  | $ | (213 | )
Schedule of Notional Amounts of Outstanding Derivative Positions | As of March 31, 2013 and December 31, 2012, the net forward notional buy (sell) position of our outstanding commodity and interest rate swap contracts that did not qualify under the normal purchase normal sale exemption were as follows (in millions):
Derivative Instruments |  | Notional Amounts
| March 31, 2013 |  | December 31, 2012
Power (MWh) |  | (16 | ) |  | (16 | )
Natural gas (MMBtu) |  | 162 |  |  | 66 |
Interest rate swaps |  | $ | 1,599 |  |  | $ | 1,602 |
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value |
| March 31, 2013 |  | December 31, 2012
| Fair Value of Derivative Assets |  | Fair Value of Derivative Liabilities |  | Fair Value of Derivative Assets |  | Fair Value of Derivative Liabilities
Derivatives designated as cash flow hedging instruments: |  |  |  |  |  |  |
Interest rate swaps | $ | 5 |  |  | $ | 174 |  |  | $ | 4 |  |  | $ | 184 |
Total derivatives designated as cash flow hedging instruments | $ | 5 |  |  | $ | 174 |  |  | $ | 4 |  |  | $ | 184 |
Derivatives not designated as hedging instruments: |  |  |  |  |  |  |
Commodity instruments | $ | 658 |  |  | $ | 696 |  |  | $ | 433 |  |  | $ | 450 |
Interest rate swaps | — |  |  | 14 |  |  | — |  |  | 16 |
Total derivatives not designated as hedging instruments | $ | 658 |  |  | $ | 710 |  |  | $ | 433 |  |  | $ | 466 |
Total derivatives | $ | 663 |  |  | $ | 884 |  |  | $ | 437 |  |  | $ | 650 |
Derivative Instruments Subject to Master Netting Arrangements [Table Text Block] | The tables below set forth our net exposure to derivative instruments after offsetting amounts subject to a master netting arrangement with the same counterparty at March 31, 2013 and December 31, 2012 (in millions):
|  | March 31, 2013
|  |  |  | Gross Amounts Not Offset on the Consolidated Condensed Balance Sheets |  |
|  | Gross Amounts Presented on our Consolidated Condensed Balance Sheets |  | Derivative Asset (Liability) not Offset on the Consolidated Condensed Balance Sheets |  | Margin/Cash (Received) Posted (1) |  | Net Amount
Derivative assets: |  |  |  |  |  |  |  |
Commodity exchange traded futures and swaps contracts |  | $ | 594 |  |  | $ | (593 | ) |  | $ | (1 | ) |  | $ | — |
Commodity forward contracts |  | 64 |  |  | (29 | ) |  | — |  |  | 35 |
Interest rate swaps |  | 5 |  |  | — |  |  | — |  |  | 5 |
Total derivative assets |  | $ | 663 |  |  | $ | (622 | ) |  | $ | (1 | ) |  | $ | 40 |
Derivative (liabilities): |  |  |  |  |  |  |  |
Commodity exchange traded futures and swaps contracts |  | $ | (655 | ) |  | $ | 593 |  |  | $ | 62 |  |  | $ | — |
Commodity forward contracts |  | (41 | ) |  | 29 |  |  | 1 |  |  | (11 | )
Interest rate swaps |  | (188 | ) |  | — |  |  | — |  |  | (188 | )
Total derivative (liabilities) |  | $ | (884 | ) |  | $ | 622 |  |  | $ | 63 |  |  | $ | (199 | )
Net derivative assets (liabilities) |  | $ | (221 | ) |  | $ | — |  |  | $ | 62 |  |  | $ | (159 | )
|  | December 31, 2012
|  |  |  | Gross Amounts Not Offset on the Consolidated Condensed Balance Sheets |  |
|  | Gross Amounts Presented on our Consolidated Condensed Balance Sheets |  | Derivative Asset (Liability) not Offset on the Consolidated Condensed Balance Sheets |  | Margin/Cash (Received) Posted (1) |  | Net Amount
Derivative assets: |  |  |  |  |  |  |  |
Commodity exchange traded futures and swaps contracts |  | $ | 385 |  |  | $ | (379 | ) |  | $ | (6 | ) |  | $ | — |
Commodity forward contracts |  | 48 |  |  | (17 | ) |  | (1 | ) |  | 30 |
Interest rate swaps |  | 4 |  |  | — |  |  | — |  |  | 4 |
Total derivative assets |  | $ | 437 |  |  | $ | (396 | ) |  | $ | (7 | ) |  | $ | 34 |
Derivative (liabilities): |  |  |  |  |  |  |  |
Commodity exchange traded futures and swaps contracts |  | $ | (424 | ) |  | $ | 379 |  |  | $ | 45 |  |  | $ | — |
Commodity forward contracts |  | (26 | ) |  | 17 |  |  | 1 |  |  | (8 | )
Interest rate swaps |  | (200 | ) |  | — |  |  | — |  |  | (200 | )
Total derivative (liabilities) |  | $ | (650 | ) |  | $ | 396 |  |  | $ | 46 |  |  | $ | (208 | )
Net derivative assets (liabilities) |  | $ | (213 | ) |  | $ | — |  |  | $ | 39 |  |  | $ | (174 | )
____________
(1) | Negative balances represent margin deposits posted with us by our counterparties related to our derivative activities that are subject to a master netting arrangement. Positive balances reflect margin deposits and natural gas and power prepayments posted by us with our counterparties related to our derivative activities that are subject to a master netting arrangement. See Note 6 for a further discussion of our collateral.
Realized Unrealized Gain Loss by Instrument | The following tables detail the components of our total mark-to-market activity for both the net realized gain (loss) and the net unrealized gain (loss) recognized from our derivative instruments in earnings and where these components were recorded on our Consolidated Condensed Statements of Operations for the periods indicated (in millions):
|  | Three Months Ended March 31,
|  | 2013 |  | 2012
Realized gain (loss)(1) |  |  |  |
Commodity derivative instruments |  | $ | 28 |  |  | $ | 118 |
Interest rate swaps |  | — |  |  | (157 | )
Total realized gain (loss) |  | $ | 28 |  |  | $ | (39 | )
Unrealized gain (loss)(2) |  |  |  |
Commodity derivative instruments |  | $ | (57 | ) |  | $ | 78 |
Interest rate swaps |  | 2 |  |  | 146 |
Total unrealized gain (loss) |  | $ | (55 | ) |  | $ | 224 |
Total mark-to-market activity, net |  | $ | (27 | ) |  | $ | 185 |
___________
(1) | Does not include the realized value associated with derivative instruments that settle through physical delivery.
(2) | In addition to changes in market value on derivatives not designated as hedges, changes in unrealized gain (loss) also includes hedge ineffectiveness and adjustments to reflect changes in credit default risk exposure.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location |
|  | Three Months Ended March 31,
|  | 2013 |  | 2012
Realized and unrealized gain (loss) |  |  |  |
Derivatives contracts included in operating revenues |  | $ | (74 | ) |  | $ | 92 |
Derivatives contracts included in fuel and purchased energy expense |  | 45 |  |  | 104 |
Interest rate swaps included in interest expense |  | 2 |  |  | 3 |
Loss on interest rate derivatives |  | — |  |  | (14 | )
Total mark-to-market activity, net |  | $ | (27 | ) |  | $ | 185 |
Derivatives Designated as Hedges | The following table details the effect of our net derivative instruments that qualified for hedge accounting treatment and are included in OCI and AOCI for the periods indicated (in millions):
| Three Months Ended March 31, |  | Three Months Ended March 31,
| Gain (Loss) Recognized in OCI (Effective Portion) |  | Gain (Loss) Reclassified from AOCI into Income (Effective Portion)(3)
| 2013 |  | 2012 |  | 2013 |  | 2012 |  | Affected Line Item on the Consolidated Condensed Statements of Operations
Commodity derivative instruments(1): |  |  |  |  |  |  |  |  |
Power derivative instruments | $ | — |  |  | $ | (15 | ) |  | $ | — |  |  | $ | 38 |  |  | Commodity revenue
Natural gas derivative instruments | — |  |  | 14 |  |  | — |  |  | (21 | ) |  | Commodity expense
Interest rate swaps(2) | 13 |  |  | 1 |  |  | (9 | ) |  | (7 | ) |  | Interest expense
Total | $ | 13 |  |  | $ | — |  |  | $ | (9 | ) |  | $ | 10 |  |  |
____________
(1) | There were no commodity derivative instruments designated as cash flow hedges during the three months ended March 31, 2013. We recorded a gain on hedge ineffectiveness of $2 million related to our commodity derivative instruments designated as cash flow hedges during the three months ended March 31, 2012.
(2) | We did not record any gain (loss) on hedge ineffectiveness related to our interest rate swaps designated as cash flow hedges during the three months ended March 31, 2013 and 2012.
(3) | Cumulative cash flow hedge losses, net of tax, remaining in AOCI were $228 million and $242 million at March 31, 2013 and December 31, 2012, respectively.

X
- Details
Name: | cpn_DerivativeInstrumentsAbstract
Namespace Prefix: | cpn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Derivative Instruments Subject to Master Netting Arrangements with the same counterparty[Table Text Block] + References No definition available. + Details
Name: | cpn_DerivativeInstrumentsSubjectToMasterNettingArrangementsTableTextBlock
Namespace Prefix: | cpn_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Realized Unrealized Gain Loss by Instrument Table Text Block + References No definition available. + Details
Name: | cpn_RealizedUnrealizedGainLossByInstrumentTableTextBlock
Namespace Prefix: | cpn_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of derivative instruments (including nonderivative instruments that are designated and qualify as hedging instruments) of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959 + Details
Name: | us-gaap_ScheduleOfDerivativesInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the notional amounts of outstanding derivative positions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 + Details
Name: | us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for other derivative instruments not designated as hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
Name: | us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration