Fair Value Measurement (Tables)

12 Months Ended

May. 31, 2015

Fair Value Disclosures [Abstract]

Schedule of the entity's assets and liabilities that are measured at fair value on a recurring basis

The following table presents our assets and liabilities that are measured at fair value on a recurring basis as of May 31, 2015 and 2014.

	2015				2014
(Dollars in thousands)	Level 1		Level 2		Level 1		Level 2
Investment securities	$	84,472	$	—	$	55,177	$	—
Deferred compensation investments	4,294		—		4,156		—
Derivative assets	—		115,276		—		209,759
Derivative liabilities	—		408,382		—		388,208

Schedule of carrying/fair value of the related individual assets and the total losses

	Level 3 Fair Value				Total Losses
(Dollars in thousands)	2015		2014		2015		2014
Nonperforming loans, net of specific reserves	$	—	$	1,669	$	—	$	—