Accumulated Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2018	Aug. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 3,016,526
Other comprehensive (loss) income before reclassifications	(6,187)	$ 35,204
Amounts reclassified from accumulated other comprehensive income (loss)	(295)	(172)
Other comprehensive (loss) income	(6,482)	35,032
Ending balance	3,345,968
Foreign Currency
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	6,550	(12,726)
Other comprehensive (loss) income before reclassifications	(3,019)	35,184
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive (loss) income	(3,019)	35,184
Ending balance	3,531	22,458
Unrealized Income on Interest Rate Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	10,449	11,382
Other comprehensive (loss) income before reclassifications	(3,168)	0
Amounts reclassified from accumulated other comprehensive income (loss)	(295)	(172)
Other comprehensive (loss) income	(3,463)	(172)
Ending balance	6,986	11,210
Other
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(656)	(1,685)
Other comprehensive (loss) income before reclassifications	0	20
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive (loss) income	0	20
Ending balance	(656)	(1,665)
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	16,343	(3,029)
Ending balance	$ 9,861	$ 32,003