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	74,712			$ 74,712
Unrealized gain (loss) on securities available for sale		(112)
Reclassification adjustment for actuarial (gain) loss on postretirement benefit obligation included in net income		26
Net income (loss) attributable to noncontrolling interest			(390)	(390)
Equity distribution to noncontrolling interest			(57)
Equity at end of period at Sep. 30, 2015	983,381	(914)	108,855	1,091,322
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	37,809			37,809
Retirement of patronage capital	(12,466)
Unrealized gain (loss) on securities available for sale		35
Reclassification adjustment for actuarial (gain) loss on postretirement benefit obligation included in net income		(68)
Net income (loss) attributable to noncontrolling interest			313	313
Equity distribution to noncontrolling interest			(59)
Equity at end of period at Sep. 30, 2016	$ 977,425	$ 556	$ 109,011	$ 1,086,992