Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on Storage transactions			$ 0	$ 15,786
Gain on Shred-it			25,876	349,738
Net income from discontinued operations	$ 16,923	$ 229,647	16,923	223,630
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	0	0	0
Income before income taxes	0	845	0	1,082
Gain on Storage transactions	0	10,943	0	15,786
Gain on Shred-it	25,876	364,254	25,876	349,738
Income tax expense on net gain	(8,953)	(146,395)	(8,953)	(142,976)
Net income from discontinued operations	$ 16,923	$ 229,647	$ 16,923	$ 223,630