Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Revenues
Member electric sales	$ 1,125,699	$ 1,101,471	$ 1,091,103
Non-member electric sales	120,234	197,497	172,102
Other	89,515	96,123	77,958
Total revenues	1,335,448	1,395,091	1,341,163
Operating expenses
Purchased power	305,045	327,445	322,059
Fuel	231,537	293,033	287,647
Production	235,398	229,933	209,816
Transmission	153,443	145,396	138,684
General and administrative	24,708	28,591	24,325
Depreciation and amortization	152,718	128,712	121,818
Coal mining	36,130	40,849	29,889
Other	18,500	19,255	18,337
Operating expenses	1,157,479	1,213,214	1,152,575
Operating margins	177,969	181,877	188,588
Other income
Interest Income	4,355	11,076	17,288
Capital credits from cooperatives	9,189	8,684	10,922
Other income	3,981	3,573	3,344
Total other income	17,525	23,333	31,554
Interest expense, net of amounts capitalized	142,570	142,357	149,463
Income taxes	0	0	0
Net margins including noncontrolling interest	52,924	62,853	70,679
Net loss attributable to noncontrolling interest	489	1,383	2,233
Net margins attributable to the Association	$ 53,413	$ 64,236	$ 72,912