Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 480,708	$ 693,520	$ 430,618
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(10,252)	(11,933)	(38,538)
Cumulative translation adjustment on Shred-it	0	6,472	0
Change in fair value of cash flow hedges	31,136	(12,156)	37
Amortization of interest rate lock agreements	1,076	1,952	1,952
Other	(115)	(738)	(350)
Other comprehensive income (loss), net of tax expense (benefit) of $19,118, ($9,813), and $1,043, respectively	21,845	(16,403)	(36,899)
Comprehensive income (loss)	$ 502,553	$ 677,117	$ 393,719