Consolidated Statements of Patronage Capital and Membership Fees (Unaudited) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Increase (Decrease) in Members' Capital
Net margin	$ 18,167		$ 13,145		$ 40,147	$ 39,103
Patronage Capital and Membership Fees
Increase (Decrease) in Members' Capital
Beginning balance	1,152,403	$ 1,130,423	1,098,600	$ 1,072,642	1,130,423	1,072,642
Net margin	18,167	21,980	13,145	25,958
Ending balance	$ 1,170,570	$ 1,152,403	$ 1,111,745	$ 1,098,600	$ 1,170,570	$ 1,111,745