Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax (expense) benefit	$ 6,157	$ (2,109)	$ (34,946)	$ (13,101)
Gain on sale of business			99,060	0
Gain on Shred-it			0	25,876
Net income from discontinued operations	6,306	1,051	61,781	21,361
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	25,768	10,773	79,094
Income (loss) before income taxes	149	3,160	(2,333)	8,586
Income tax (expense) benefit	(242)	(2,109)	678	(4,148)
Gain on sale of business	0	0	99,060	0
Gain on Shred-it	0	0	0	25,876
Income tax benefit (expense) on net gain	6,399	0	(35,624)	(8,953)
Net income from discontinued operations	$ 6,306	$ 1,051	$ 61,781	$ 21,361