Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Cash flows from operating activities:
Net loss	$ (125)		$ (9)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense(1)	158	[1]	151	[1]
Deferred income taxes	(7)		(1)
Loss on disposition of assets	2		2
Unrealized mark-to-market activity, net	55	[2]	(224)	[2]
(Income) from unconsolidated investments in power plants	(8)		(9)
Stock-based compensation expense	8		6
Other	(2)		0
Change in operating assets and liabilities:
Accounts receivable	(45)		211
Derivative instruments, net	(36)		(66)
Other assets	(73)		20
Accounts payable and accrued expenses	(91)		(153)
Settlement of non-hedging interest rate swaps	0		151
Other liabilities	7		(8)
Net cash provided by (used in) operating activities	(157)		71
Cash flows from investing activities:
Purchases of property, plant and equipment	(176)		(181)
Settlement of non-hedging interest rate swaps	0		(151)
Decrease in restricted cash	54		23
Purchases of deferred transmission credits	0		(8)
Other	0		3
Net cash used in investing activities	(122)		(314)
Cash flows from financing activities:
Repayment under First Lien Term Loans	(6)		(4)
Borrowings from project financing, notes payable and other	73		114
Repayments of project financing, notes payable and other	(36)		(34)
Financing costs	(9)		(5)
Stock repurchases	(75)		(6)
Proceeds from exercises of stock options	9		0
Other	1		(4)
Net cash provided by (used in) financing activities	(43)		61
Net decrease in cash and cash equivalents	(322)		(182)
Cash and cash equivalents, beginning of period	1,284		1,252
Cash and cash equivalents, end of period	962		1,070
Cash paid during the period for:
Interest, net of amounts capitalized	213		226
Income taxes	5		6
Supplemental disclosure of non-cash investing activities:
Change in capital expenditures included in accounts payable	$ 17		$ 47

[1] Includes depreciation and amortization included in fuel and purchased energy expense and interest expense on our Consolidated Condensed Statements of Operations

[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.