CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Income Statement [Abstract]
Interest income	$ 253,633	$ 238,740	$ 756,074	$ 711,266
Interest expense	(171,189)	(156,850)	(504,013)	(471,677)
Net interest income	82,444	81,890	252,061	239,589
Provision for loan losses	1,735	(2,304)	(4,067)	3,475
Net interest income after provision for loan losses	84,179	79,586	247,994	243,064
Non-interest income:
Fee and other income	5,604	5,020	17,336	19,249
Derivative losses	(243,036)	(98,770)	(356,237)	(223,209)
Results of operations of foreclosed assets	1,472	(1,369)	1,605	(33,059)
Total non-interest income	(235,960)	(95,119)	(337,296)	(237,019)
Non-interest expense:
Salaries and employee benefits	(11,346)	(10,949)	(33,779)	(32,274)
Other general and administrative expenses	(11,006)	(7,059)	(31,639)	(22,514)
Losses on early extinguishment of debt	(333)	(703)	(333)	(703)
Other	(509)	(7)	(875)	50
Total non-interest expense	(23,194)	(18,718)	(66,626)	(55,441)
Loss before income taxes	(174,975)	(34,251)	(155,928)	(49,396)
Income tax benefit (expense)	593	55	153	(100)
Net loss	(174,382)	(34,196)	(155,775)	(49,496)
Less: Net loss attributable to noncontrolling interests	1,401	217	1,982	213
Net loss attributable to CFC	$ (172,981)	$ (33,979)	$ (153,793)	$ (49,283)