Equity Equity Components (Details) - USD ($) $ in Thousands	May 31, 2016	May 31, 2015	May 31, 2014	May 31, 2013
Components of equity
Year-to-date derivative forward value income (loss)	$ (220,827)	$ (114,665)
Prior years cumulative derivative forward value and foreign currency adjustments	(287,077)	(172,412)
Total Cumulative Derivative Forward Value and Foreign Currency Adjustments	(507,904)	(287,077)
Retained equity	790,234	880,242
Accumulated other comprehensive income	1,058	4,080	$ 3,649
Total CFC equity	791,292	884,322
Noncontrolling interests	26,086	27,464
Total equity	817,378	911,786	970,374	$ 811,261
Membership fees
Components of equity
Total members' equity	974	976
Education fund
Components of equity
Total members' equity	1,798	1,767
Retained Earnings, Appropriated Membership Fees and Education Fund [Member]
Components of equity
Total members' equity	2,772	2,743
Total equity	2,772	2,743	2,751	2,505
Members' capital reserve
Components of equity
Total members' equity	713,853	668,980
Total equity	587,219	501,731	485,447	410,259
Allocated net income
Components of equity
Total members' equity	587,219	501,731
Total equity	713,853	668,980	630,340	591,581
Unallocated net income (loss)
Components of equity
Total members' equity	(5,706)	(6,135)
Unallocated net income (loss)
Components of equity
Total equity	$ (513,610)	$ (293,212)	$ (178,650)	$ (213,255)