Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 26	$ 75
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	124	125
Expenses related to Cascade Crossing	52	0
(Decrease) increase in net liabilities from price risk management activities	(16)	(64)
Regulatory deferral - price risk management activities	16	63
Deferred income taxes	(1)	43
Pension and other postretirement benefits	20	14
Regulatory deferral of settled derivative instruments	10	4
Decoupling mechanism deferrals, net of amortization	5	(4)
Power cost deferrals, net of amortization	(3)	4
Allowance for equity funds used during construction	(4)	(3)
Other non-cash income and expenses, net	13	7
Changes in working capital:
Decrease in receivables	39	42
Decrease (increase) in margin deposits, net	12	11
Income tax refund received	0	8
Decrease in payables and accrued liabilities	(13)	(57)
Other working capital items, net	11	(8)
Other, net	(2)	(1)
Net cash provided by operating activities	279	267
Cash flows from investing activities:
Capital expenditures	(260)	(137)
Proceeds from sale of solar power facility	0	10
Sales of nuclear decommissioning trust securities	14	13
Purchases of nuclear decommissioning trust securities	(15)	(13)
Other, net	2	(1)
Net cash used in investing activities	(259)	(128)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	150	0
Payments on long-term debt	50	0
Proceeds from issuance of common stock, net of issuance costs	47	0
Borrowings on short-term debt	35	0
Payments on short-term debt	(35)	0
Maturities of commercial paper, net	(17)	(30)
Dividends paid	(41)	(41)
Net cash used in financing activities	87	(71)
Increase in cash and cash equivalents	107	68
Cash and cash equivalents, beginning of period	12	6
Cash and cash equivalents, end of period	119	74
Supplemental cash flow information is as follows:
Cash paid for interest, net of amounts capitalized	45	48
Cash paid for income taxes	6
Non-cash investing and financing activities:
Accrued dividends payable	21	21
Accrued capital additions	34	14
Preliminary engineering transferred to Construction work in progress from Other noncurrent assets	9	0
Debt issuance costs	$ (2)	$ 0