Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 49	$ 69
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	62	56
Increase (decrease) in net liabilities from price risk management activities	21	(29)
Regulatory deferral - price risk management activities	(22)	29
Deferred income taxes	24	25
Power cost deferrals, net of amortization	3	4
Allowance for equity funds used during construction	(1)	(1)
Other non-cash income and expenses, net	14	9
Changes in working capital:
Decrease (increase) in receivables	9	(1)
(Increase) decrease in margin deposits, net	(18)	3
Income tax refund received	8	8
Decrease in payables and accrued liabilities	(18)	(10)
Other working capital items, net	(24)	(16)
Other, net	3	0
Net cash provided by operating activities	110	146
Cash flows from investing activities:
Capital expenditures	(69)	(69)
Sale of solar power facility	10	0
Sales of Nuclear decommissioning trust securities	7	18
Purchases of Nuclear decommissioning trust securities	(7)	(19)
Other, net	1	0
Net cash used in investing activities	(58)	(70)
Cash flows from financing activities:
Payments on long-term debt	0	(10)
Maturities of commercial paper, net	(30)	(19)
Dividends paid	(20)	(20)
Noncontrolling interests’ capital distributions	0	(4)
Net cash used in financing activities	(50)	(53)
Increase in cash and cash equivalents	2	23
Cash and cash equivalents, beginning of period	6	4
Cash and cash equivalents, end of period	8	27
Supplemental cash flow information is as follows:
Cash paid for interest, net of amounts capitalized	13	15
Cash paid for income taxes	0	1
Non-cash investing and financing activities:
Accrued capital additions	8	9
Accrued dividends payable	$ 21	$ 20