Accumulated Other Comprehensive Income (Loss) (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Equity [Abstract]
Amortization of interest rate locks	$ (783)	$ (783)
Tax benefit	295	295
Amortization of interest rate locks, net of tax	$ (488)	$ (488)