Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax benefit (expense)	$ 624	$ (9,851)	$ (41,103)	$ (10,992)
(Loss) gain on sale of business			99,060	0
Gain on Shred-it		25,900	0	25,876
Net (loss) income from discontinued operations	(628)	18,427	55,475	20,310
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	25,845	10,773	53,326
(Loss) income before income taxes	(43)	2,402	(2,482)	5,426
Income tax benefit (expense)	18	(898)	920	(2,039)
(Loss) gain on sale of business	(1,209)	0	99,060	0
Gain on Shred-it	0	25,876	0	25,876
Income tax benefit (expense) on net gain	606	(8,953)	(42,023)	(8,953)
Net (loss) income from discontinued operations	$ (628)	$ 18,427	$ 55,475	$ 20,310