Consolidated Statements Of Changes In Equities And Margins - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance		$ 181,637,381		$ 176,925,299	$ 181,637,381	$ 176,925,299	$ 175,795,865
Assignable margins	$ 5,632,088	2,628,930	$ 3,411,797	6,046,730	5,813,856	6,502,852	6,515,545
Retirement/net transfer of capital credits					(3,265,201)	(3,190,124)	(5,130,381)
Unclaimed capital credit retirements					1,175,962	1,298,410	(350,776)
Memberships and donations received					153,527	100,944	95,046
Balance	185,515,525		181,637,381		185,515,525	181,637,381	176,925,299
Memberships [Member]
Balance		1,661,744		1,631,569	1,661,744	1,631,569	1,600,058
Assignable margins					0	0	0
Retirement/net transfer of capital credits					0	0	0
Unclaimed capital credit retirements					0	0	0
Memberships and donations received					29,270	30,175	31,511
Balance	1,691,014		1,661,744		1,691,014	1,661,744	1,631,569
Other Equities And Margins [Member]
Balance		12,527,856		11,158,677	12,527,856	11,158,677	11,445,918
Assignable margins					0	0	0
Retirement/net transfer of capital credits					0	0	0
Unclaimed capital credit retirements					1,175,962	1,298,410	(350,776)
Memberships and donations received					124,257	70,769	63,535
Balance	13,828,075		12,527,856		13,828,075	12,527,856	11,158,677
Patronage Capital [Member]
Balance		$ 167,447,781		$ 164,135,053	167,447,781	164,135,053	162,749,889
Assignable margins					5,813,856	6,502,852	6,515,545
Retirement/net transfer of capital credits					(3,265,201)	(3,190,124)	(5,130,381)
Unclaimed capital credit retirements					0	0	0
Memberships and donations received					0	0	0
Balance	$ 169,996,436		$ 167,447,781		$ 169,996,436	$ 167,447,781	$ 164,135,053