Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax benefit (expense)	$ (35,313)	$ (15,057)	$ (138,184)
Gain on sale of business	96,400	0	0
Gain on Shred-it		25,457	354,071
Net income from discontinued operations	58,654	23,422	244,915
Shred-it Partnership
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business		25,500
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	10,773	105,559	109,686
(Loss) income before income taxes, excluding gains from sale transactions and investments	(2,433)	10,622	13,242
Income tax benefit (expense)	706	(3,930)	(4,900)
Gain on sale of business	96,400	0	0
Income tax expense on net gain	(36,019)	(11,127)	(133,284)
Net income from discontinued operations	58,654	23,422	244,915
Discontinued Operations | Shred-it Partnership
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on Shred-it	0	25,457	354,071
Discontinued Operations | Storage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business	$ 0	$ 2,400	$ 15,786