Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 87,187	$ 87,392
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of electric plant in service	62,336	59,346
Amortization of nuclear fuel	33,942	33,621
Deferred income taxes, net	35,990	45,479
Allowance for equity funds used during construction	(10,215)	(7,465)
Other amortization and accretion	14,470	12,345
Gain on sale of property, plant and equipment	(2,092)	0
Other operating activities	(3,843)	(484)
Change in:
Accounts receivable	(47,331)	(35,097)
Inventories	(1,000)	(4,772)
Net undercollection of fuel revenues	(1,233)	(8,362)
Prepayments and other	(4,381)	(5,471)
Accounts payable	3,557	(3,729)
Taxes accrued	7,669	6,794
Other current liabilities	3,255	9,654
Deferred charges and credits	(3,674)	(4,340)
Net cash provided by operating activities	174,637	184,911
Cash flows from investing activities:
Cash additions to utility property, plant and equipment	(189,273)	(165,303)
Cash additions to nuclear fuel	(28,772)	(19,895)
Capitalized interest and AFUDC:
Utility property, plant and equipment	(16,056)	(11,985)
Nuclear fuel	(3,797)	(3,911)
Allowance for equity funds used during construction	10,215	7,465
Decommissioning trust funds:
Purchases, including funding of $3.4 million	(54,343)	(36,413)
Sales and maturities	47,355	29,419
Proceeds from sale of property, plant and equipment	2,395	0
Other investing activities	4,438	4,856
Net cash used for investing activities	(227,838)	(195,767)
Cash flows from financing activities:
Dividends paid	(33,261)	(31,379)
Borrowings under the revolving credit facility:
Proceeds	186,215	34,167
Payments	(111,039)	(40,831)
Other financing activities	(896)	(210)
Net cash provided by (used for) financing activities	41,019	(38,253)
Net decrease in cash and cash equivalents	(12,182)	(49,109)
Cash and cash equivalents at beginning of period	25,592	111,057
Cash and cash equivalents at end of period	$ 13,410	$ 61,948