Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2017	May 31, 2016
Equity [Abstract]
Amortization of interest rate locks	$ (1,714)	$ (3,130)
Tax benefit	638	1,178
Amortization of interest rate locks, net of tax	(1,076)	(1,952)
Cumulative translation adjustment on Shred-it	0	(10,381)
Tax benefit	0	3,909
Cumulative translation adjustment on Shred-it, net of tax	$ 0	$ (6,472)