Consolidated Statements of Equity - USD ($) $ in Thousands	Patronage capital	Accumulated other comprehensive income (loss)	Noncontrolling interest	Total
Equity at beginning of year at Dec. 31, 2016	$ 961,364	$ (286)	$ 109,147
Change in Equity
Net margins attributable to the Association	23,526			$ 23,526
Unrealized gain on securities available for sale		24
Reclassification adjustment for actuarial gain on postretirement benefit obligation included in net income		(20)
Net comprehensive income (loss) attributable to noncontrolling interest			296	296
Equity at end of year at Mar. 31, 2017	984,890	(282)	109,443	1,094,051
Equity at beginning of year at Dec. 31, 2017	1,003,020	(210)	111,295	1,114,105
Change in Equity
Net margins attributable to the Association	8,094			8,094
Reclassification adjustment for unrealized gain on securities available for sale included in net income		(159)
Reclassification adjustment for actuarial gain on postretirement benefit obligation included in net income		(20)
Net comprehensive income (loss) attributable to noncontrolling interest			797	797
Equity distribution to noncontrolling interest			(2,858)
Equity at end of year at Mar. 31, 2018	$ 1,011,114	$ (389)	$ 109,234	$ 1,119,959