Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net margin	$ 20,598	$ 15,369
Adjustments to reconcile net margin to net cash provided by operating activities:
Depreciation and amortization, including nuclear fuel	87,413	76,642
Accretion cost	8,016	6,382
Amortization of deferred gains	(447)	(447)
Allowance for equity funds used during construction	(177)	(173)
Deferred outage costs	(24,869)	(17,169)
Deferral of Hawk Road and Smith Energy Facilities effect on net margin		(14,315)
Gain on sale of investments	849	(4,687)
Regulatory deferral of costs associated with nuclear decommissioning	(5,814)	1,222
Other	(1,685)	(1,617)
Change in operating assets and liabilities:
Receivables	4,044	10,471
Inventories	5,253	18,031
Prepayments and other current assets	273	(30,174)
Accounts payable	(39,787)	(39,364)
Accrued interest	(5,528)	(5,703)
Accrued taxes	(13,160)	(8,914)
Other current liabilities	(9,777)	(10,545)
Member power bill prepayments	(6,779)	23,732
Total adjustments	(2,175)	3,372
Net cash provided by operating activities	18,423	18,741
Cash flows from investing activities:
Property additions	(259,447)	(157,332)
Activity in nuclear decommissioning trust fund - Purchases	(129,886)	(111,750)
Activity in nuclear decommissioning trust fund - Proceeds	128,179	110,666
Increase in restricted cash and investments	(9,419)	(586)
Decrease (increase) in restricted short-term investments	2,663	(4,668)
Activity in other long-term investments - Purchases	(14,267)	(12,045)
Activity in other long-term investments - Proceeds	11,639	11,214
Other	3,147	(5,278)
Net cash used in investing activities	(267,391)	(169,779)
Cash flows from financing activities:
Long-term debt proceeds	7,998	113,718
Long-term debt payments	(36,677)	(37,319)
Increase in short-term borrowings, net	171,280	109,360
Other	4,422	(408)
Net cash provided by financing activities	147,023	185,351
Net (decrease) increase in cash and cash equivalents	(101,945)	34,313
Cash and cash equivalents at beginning of period	213,038	237,391
Cash and cash equivalents at end of period	111,093	271,704
Cash paid for -
Interest (net of amounts capitalized)	66,950	69,258
Supplemental disclosure of non-cash investing and financing activities:
Change in asset retirement obligations	(10,425)
Change in accrued property additions	(79,336)	(22,510)
Interest paid-in-kind	$ 10,606	$ 8,065