Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 61	$ 50
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	82	75
Increase in net liabilities from price risk management activities	2	53
Regulatory deferrals-price risk management activities	(2)	(53)
Deferred income taxes	14	10
Pension and other postretirement benefits	7	9
Allowance for equity funds used during construction	(7)	(4)
Other non-cash income and expenses, net	4	5
Changes in working capital:
Decrease in accounts receivable and unbilled revenues	46	37
Decrease (increase) in inventories	1	(13)
Increase in margin deposits, net	(7)	(9)
Decrease in accounts payable and accrued liabilities	(11)	(1)
Other working capital items, net	(16)	(20)
Other, net	(13)	(5)
Net cash provided by operating activities	161	134
Cash flows from investing activities:
Capital expenditures	(131)	(178)
Sales tax refund received related to Tucannon River Wind Farm	0	12
Sales of Nuclear decommissioning trust securities	6	4
Purchases of Nuclear decommissioning trust securities	(6)	(5)
Other, net	(2)	0
Net cash used in investing activities	(133)	(167)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	140	75
Payments on long-term debt	(133)	(120)
Change in short-term debt	(6)	0
Dividends paid	(27)	(22)
Payments on capital leases	(1)	0
Debt issuance costs	(1)	0
Net cash used in financing activities	(28)	(67)
Decrease in cash and cash equivalents	0	(100)
Cash and cash equivalents, beginning of period	4	127
Cash and cash equivalents, end of period	4	27
Supplemental cash flow information is as follows:
Cash paid for interest, net of amounts capitalized	10	14
Non-cash investing and financing activities:
Accrued capital additions	49	62
Accrued dividends payable	28	22
Assets obtained under capital lease	$ 54	$ 0