Consolidated Statements of Cash Flows Statement (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 425	$ 442
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	456	414
Deferred income taxes and amortization of investment tax credits	274	435
Changes in regulatory assets and liabilities	(23)	14
Other, net	(21)	(53)
Changes in other operating assets and liabilities:
Accounts receivable and other assets	(8)	33
Derivative collateral, net	44	(107)
Inventories	(34)	(17)
Income taxes receivable, net	333	(79)
Accounts payable and other liabilities	6	(38)
Net cash flows from operating activities	1,452	1,044
Cash flows from investing activities:
Capital expenditures	(1,069)	(1,250)
Other, net	2	(9)
Net cash flows from investing activities	(1,067)	(1,259)
Cash flows from financing activities:
Net (repayments of) proceeds from short-term debt	(36)	34
Proceeds from long-term debt	399	0
Proceeds from equity contributions	0	100
Repayments and redemptions of long-term debt and capital lease obligations	(74)	(1)
Preferred stock dividends	(2)	(2)
Common stock dividends	(550)	0
Other, net	(2)	(1)
Net cash flows from financing activities	(265)	130
Net change in cash and cash equivalents	120	(85)
Cash and cash equivalents at beginning of period	31	117
Cash and cash equivalents at end of period	$ 151	$ 32