Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 29,129	$ 13,267	$ 59,446	$ 27,439
Income taxes	(68,636)	(65,270)	(126,607)	(118,892)
Net income	137,737	121,950	298,845	258,158
Reclassifications out of Accumulated Other Comprehensive Income (Loss) | Unrealized Income on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income taxes	(106)	230	(212)	459
Net income	172	(385)	344	(770)
Reclassifications out of Accumulated Other Comprehensive Income (Loss) | Unrealized Income on Cash Flow Hedges | Interest Rate Locks
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 278	$ (615)	$ 556	$ (1,229)