Condensed Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net margin	$ 24,398	$ 28,828
Adjustments to reconcile net margin to net cash provided by operating activities:
Depreciation and amortization, including nuclear fuel	156,664	145,590
Accretion cost	9,716	9,125
Amortization of deferred gains	(2,830)	(2,830)
Allowance for equity funds used during construction	(1,432)	(1,404)
Deferred outage costs	(13,379)	(36,672)
Deferral of Hawk Road and Smith Energy Facilities effect on net margin	(14,559)	(11,072)
Gain on sale of investments	(5,625)	(10,324)
Regulatory deferral of costs associated with nuclear decommissioning	165	5,553
Other	(3,908)	(3,622)
Change in operating assets and liabilities:
Receivables	(34,699)	(54,078)
Inventories	7,591	1,171
Prepayments and other current assets	(2,826)	(1,674)
Accounts payable	(43,758)	19,553
Accrued interest	(7,599)	(22,796)
Accrued taxes	(4,389)	(7,920)
Other current liabilities	(3,644)	1,376
Member power bill prepayments	(8,331)	(41,957)
Total adjustments	27,157	(11,981)
Net cash provided by operating activities	51,555	16,847
Cash flows from investing activities:
Property additions	(346,654)	(397,229)
Plant acquisition		(529,310)
Activity in decommissioning fund - Purchases	(418,240)	(557,748)
Activity in decommissioning fund - Proceeds	415,247	554,710
Decrease in restricted cash and cash equivalents	22,378	2,530
Decrease in restricted short-term investments	43,601	81,660
Increase in investment in associated organizations	(33)	(603)
Activity in other long-term investments - Purchases	(2,993)	(824)
Activity in other long-term investments - Proceeds	10,846	700
Activity on interest rate options - Purchases/Collateral returned	(43,070)
Activity on interest rate options - Collateral received	20,690
Other	11,740	(3,955)
Net cash used in investing activities	(286,488)	(850,069)
Cash flows from financing activities:
Long-term debt proceeds	79,194	793,999
Long-term debt payments	(68,678)	(260,981)
Increase in short-term borrowings, net	187,029	47,694
Other	3,038	(1,756)
Net cash provided by financing activities	200,583	578,956
Net decrease in cash and cash equivalents	(34,350)	(254,266)
Cash and cash equivalents at beginning of period	443,671	672,212
Cash and cash equivalents at end of period	409,321	417,946
Cash paid for -
Interest (net of amounts capitalized)	115,719	126,758
Supplemental disclosure of non-cash investing and financing activities:
Change in plant expenditures included in accounts payable	$ (14,733)	$ 30,335