Derivative Instruments (Details 4) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011		Jun. 30, 2010
Derivatives included in OCI and AOCI [Line Items]
Gain (loss) recognized in OCI (effective portion)	$ (48)	$ (63)	$ 58		$ 52
Gain (loss) reclassified from AOCI into income (effective portion)	31	(8)	(44)		(22)
Gain (loss) reclassified from AOCI into income (ineffective portion)		3			1
Interest Rate Swaps
Derivatives included in OCI and AOCI [Line Items]
Gain (loss) recognized in OCI (effective portion)	(39)	(47)	(36)		79
Gain (loss) reclassified from AOCI into income (effective portion)	53	54	79	[1]	100
Gain (loss) reclassified from AOCI into income (ineffective portion)	1	3	1		1
Commodity instruments
Derivatives included in OCI and AOCI [Line Items]
Gain (loss) recognized in OCI (effective portion)	(9)	(16)	94		(27)
Gain (loss) reclassified from AOCI into income (effective portion)	(22)	(62)	(123)	[2]	(122)
Gain (loss) reclassified from AOCI into income (ineffective portion)	$ (1)		$ (1)

[1] Included in operating revenues and fuel and purchased energy expense on our Consolidated Condensed Statements of Operations.

[2] Reclassification of losses from OCI to earnings for the six months ended June 30, 2011 consisted of $17 million in losses from the reclassification of interest rate contracts due to settlement, $15 million in losses from terminated interest rate contracts due to the repayment of project debt in June 2011, and $91 million in losses from existing interest rate contracts reclassified from OCI into earnings due to the refinance of variable rate First Lien Credit Facility term loans.