CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (51,516)	$ (18,927)	$ 192,926
Other comprehensive income (loss):
Unrealized gains (losses) on available-for-sale investment securities	3,468	4,295	(1,455)
Unrealized losses on foreclosed assets	(5,575)	(1,938)	(2,310)
Reclassification of derivative gains to net income	(888)	(959)	(983)
Defined benefit plan adjustments	(31)	(977)	0
Other comprehensive income (loss)	(3,026)	421	(4,748)
Total comprehensive income (loss)	(54,542)	(18,506)	188,178
Less: Total comprehensive (income) loss attributable to noncontrolling interest	1,867	(95)	(2,843)
Total comprehensive income (loss) attributable to CFC	$ (52,675)	$ (18,601)	$ 185,335