Consolidated Statement of Equity - USD ($) $ in Thousands	Patronage capital	Accumulated other comprehensive income (loss)	Noncontrolling interest	Total
Equity at beginning of period at Dec. 31, 2014	$ 908,669	$ (828)	$ 109,302
Change in Equity
Net margins attributable to the Association	26,410			$ 26,410
Unrealized loss on securities available for sale		(23)
Reclassification adjustment for actuarial (gain) loss on postretirement benefit obligation included in net income		17
Net income (loss) attributable to noncontrolling interest			(287)	(287)
Equity at end of period at Jun. 30, 2015	935,079	(834)	109,015	1,043,260
Equity at beginning of period at Dec. 31, 2015	952,082	589	108,757	1,061,428
Change in Equity
Net margins attributable to the Association	20,070			20,070
Retirement of patronage capital	(12,466)
Unrealized loss on securities available for sale		(1)
Reclassification adjustment for actuarial (gain) loss on postretirement benefit obligation included in net income		(45)
Net income (loss) attributable to noncontrolling interest			181	181
Equity distribution to noncontrolling interest			(59)
Equity at end of period at Jun. 30, 2016	$ 959,686	$ 543	$ 108,879	$ 1,069,108