Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Nov. 30, 2016	Aug. 31, 2016	Nov. 30, 2015	Aug. 31, 2015	Nov. 30, 2016	Nov. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of interest rate locks	$ (615)		$ (783)		$ (1,229)	$ (1,565)
Tax benefit	230		295		459	589
Amortization of interest rate locks, net of tax	(385)		(488)		(770)	(976)
Total amount reclassified out of accumulated other comprehensive income	(385)	$ (385)	(6,960)	$ (488)
Accumulated Translation Adjustment on Investment Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax benefit	0		3,909		0	3,909
Cumulative translation adjustment on Shred-it	0		(10,381)		0	(10,381)
Total amount reclassified out of accumulated other comprehensive income	$ 0		$ (6,472)		$ 0	$ (6,472)