Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax (expense) benefit	$ (146,395)	$ (11,739)	$ (142,976)	$ (14,730)
Gain on Storage Transactions			15,786	34,137
(Loss) gain on investment in Shred-it Partnership(1)			(24,288)	6,619
Gain on sale of investment in Shred-it Partnership			374,026	0
Net income from discontinued operations	229,647	16,711	223,630	20,914
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	10,594	0	31,379
Income (loss) before income taxes	845	(5,687)	1,082	(5,112)
Income tax (expense) benefit	(336)	2,206	(421)	1,966
Gain on Storage Transactions	10,943	34,137	15,786	34,137
(Loss) gain on investment in Shred-it Partnership(1)	(9,772)	0	(24,288)	6,619
Gain on sale of investment in Shred-it Partnership	374,026	0	374,026	0
Income tax expense on net gain (loss)	(146,059)	(13,945)	(142,555)	(16,696)
Net income from discontinued operations	$ 229,647	$ 16,711	$ 223,630	$ 20,914