Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 91,761	$ 91,112
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of electric plant in service	66,994	63,097
Amortization of Nuclear Fuel Lease	32,494	33,088
Deferred income taxes, net	47,457	48,457
Allowance for equity funds used during construction	(2,209)	(5,867)
Other amortization and accretion	14,934	12,102
Gain on sale of property, plant and equipment	0	(545)
Net gains on sale of decommissioning trust funds	(9,122)	(5,570)
Other operating activities	(762)	871
Change in:
Accounts receivable	(39,298)	(46,371)
Inventories	(2,988)	(16)
Net under/over-collection of fuel revenues	13,888	(11,766)
Prepayments and other	(5,120)	(4,467)
Accounts payable	525	6,994
Taxes accrued	6,539	4,560
Interest accrued	5,741	6,700
Other current liabilities	(138)	1,218
Deferred charges and credits	(1,950)	(16,817)
Net cash provided by operating activities	218,746	176,780
Cash flows from investing activities:
Cash additions to utility property, plant and equipment	(140,367)	(168,830)
Cash additions to nuclear fuel	(31,618)	(29,929)
Capitalized interest and AFUDC:
Utility property, plant and equipment	(4,382)	(10,031)
Nuclear fuel and other	(3,831)	(3,738)
Allowance for equity funds used during construction	2,209	5,867
Decommissioning trust funds:
Purchases, including funding of $3.4 million	(80,785)	(66,463)
Sales and maturities	76,498	60,165
Proceeds from sale of property, plant, and equipment	0	3,251
Other investing activities	(204)	3,383
Net Cash Provided by (Used in) Investing Activities	(182,480)	(206,325)
Cash flows from financing activities:
Dividends paid	(39,747)	(37,021)
Borrowings under the revolving credit facility:
Proceeds	532,332	269,977
Payments	(446,005)	(356,523)
Payment on maturing senior notes	(50,000)	0
Payment on maturing Pollution Control Bond	(33,300)	0
Proceeds from issuance of senior notes	0	157,052
Other financing activities	(906)	(2,045)
Net cash provided by financing activities	(37,626)	31,440
Net increase in cash and cash equivalents	(1,360)	1,895
Cash and cash equivalents at beginning of period	8,420	8,149
Cash and cash equivalents at end of period	$ 7,060	$ 10,044