Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 187	$ 193	$ 172
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	345	321	305
Deferred income taxes	70	37	40
Allowance for equity funds used during construction	(12)	(21)	(21)
Pension and other postretirement benefits	24	28	34
Unrealized losses on non-qualified benefit plan trust assets	2	5	6
Decoupling mechanism deferrals, net of amortization	(22)	(6)	14
Other non-cash income and expenses, net	29	7	22
Changes in working capital:
(Increase) in receivables and unbilled revenues	(3)	(9)	(11)
(Increase) decrease in margin deposits	(3)	25	(22)
Increase in payables and accrued liabilities	5	15	6
Other working capital items, net	1	(4)	(4)
Contribution to non-qualified employee benefit trust	(8)	(10)	(9)
Other, net	(18)	(28)	(12)
Net cash provided by operating activities	597	553	520
Cash flows from investing activities:
Capital expenditures	(514)	(584)	(598)
Purchases of nuclear decommissioning trust securities	(18)	(25)	(19)
Sales of nuclear decommissioning trust securities	21	27	22
Distribution from nuclear decommissioning trust	0	0	50
Sales tax refund received - Tucannon River Wind Farm	0	0	23
Other, net	(3)	(3)	0
Net cash used in investing activities	(514)	(585)	(522)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	225	290	145
Payments on long-term debt	(150)	(133)	(442)
Proceeds from issuance of common stock, net of issuance costs	0	0	271
(Maturities) issuances of commercial paper, net	0	(6)	6
Dividends paid	(118)	(110)	(97)
Other	(7)	(7)	(4)
Net cash (used in) provided by financing activities	(50)	34	(121)
Increase (decrease) in cash and cash equivalents	33	2	(123)
Cash and cash equivalents, beginning of year	6	4	127
Cash and cash equivalents, end of year	39	6	4
Supplemental disclosures of cash flow information:
Cash paid for interest, net of amounts capitalized	110	104	108
Cash paid for income taxes	18	16	3
Non-cash investing and financing activities:
Accrued capital additions	53	50	32
Accrued dividends payable	31	30	28
Assets obtained under leasing arrangements	$ 87	$ 78	$ 0

The deferral, which can be either a positive or negaitive amount depending on whether a collection from or refund to customers results, of the amounts recorded in net income for energy useage by customers on a weather adjusted basis that is different from base rates as determined under the Company's decoupling mechanism, expected to be recovered or refunded in future periods.

No definition available.