Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating Activities:
Net income	$ 97,213	$ 84,779
Non-cash items included in net income:
Depreciation and amortization	122,414	109,522
Provision for deferred income taxes	87,246	12,381
Power and natural gas cost amortizations (deferrals), net	11,422	10,004
Amortization of debt expense	2,595	2,651
Amortization of investment in exchange power	1,838	1,838
Stock-based compensation expense	6,261	5,263
Equity-related AFUDC	(6,306)	(5,891)
Pension and other postretirement benefit expense	29,076	28,179
Amortization of Spokane Energy contract	10,904	10,023
Gain on sale of Ecova	0	(710)
Decoupling regulatory deferral	(24,693)	(5,146)
Other	(15,163)	4,429
Contributions to defined benefit pension plan	(12,000)	(12,000)
Cash paid for settlement of interest rate swap agreements	(53,966)	0
Changes in working capital components:
Accounts and notes receivable	53,726	49,524
Materials and supplies, fuel stock and natural gas stored	(3,932)	6,621
Increase in collateral posted for derivative instruments	(19,754)	(9,917)
Income taxes receivable	(25,222)	43,266
Other current assets	(8,486)	3,408
Accounts payable	(17,206)	(32,378)
Income taxes payable	713	158
Other current liabilities	17,438	5,240
Net cash provided by operating activities	254,118	311,244
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(288,072)	(272,801)
Other capital expenditures	(270)	(852)
Cash paid in acquisition, net	0	(95)
Other	(26,611)	2,646
Net cash used in investing activities	(314,953)	(271,102)
Financing Activities:
Net increase in borrowings from committed line of credit	82,000	25,000
Proceeds from issuance of long-term debt	70,000	0
Redemption and maturity of long-term debt	(92,375)	(2,174)
Maturity of nonrecourse long-term debt of Spokane Energy	0	(1,431)
Issuance of common stock	66,756	1,397
Repurchase of common stock	0	(2,920)
Cash dividends paid	(65,172)	(61,828)
Other	(3,774)	(11,015)
Net cash provided by (used in) financing activities	57,435	(52,971)
Net decrease in cash and cash equivalents	(3,400)	(12,829)
Cash and cash equivalents at beginning of period	10,484	22,143
Cash and cash equivalents at end of period	$ 7,084	$ 9,314