Accumulated Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Nov. 30, 2017	Aug. 31, 2017	Nov. 30, 2016	Aug. 31, 2016	Nov. 30, 2017	Nov. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ 2,302,793			$ 2,302,793
Other comprehensive (loss) income before reclassifications	$ (11,394)	35,204	$ 18,741	$ (11,923)
Amounts reclassified from accumulated other comprehensive income (loss)	(172)	(172)	385	385
Other comprehensive (loss) income	(11,566)	35,032	19,126	(11,538)	23,466	$ 7,588
Ending balance	2,553,033				2,553,033
Foreign Currency
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	22,458	(12,726)	(2,359)	(2,474)	(12,726)	(2,474)
Other comprehensive (loss) income before reclassifications	(11,374)	35,184	(7,650)	115
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Other comprehensive (loss) income	(11,374)	35,184	(7,650)	115
Ending balance	11,084	22,458	(10,009)	(2,359)	11,084	(10,009)
Unrealized Income on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	11,210	11,382	(32,482)	(20,830)	11,382	(20,830)
Other comprehensive (loss) income before reclassifications	0	0	26,390	(12,037)
Amounts reclassified from accumulated other comprehensive income (loss)	(172)	(172)	385	385
Other comprehensive (loss) income	(172)	(172)	26,775	(11,652)
Ending balance	11,038	11,210	(5,707)	(32,482)	11,038	(5,707)
Other
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,665)	(1,685)	(1,571)	(1,570)	(1,685)	(1,570)
Other comprehensive (loss) income before reclassifications	(20)	20	1	(1)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Other comprehensive (loss) income	(20)	20	1	(1)
Ending balance	(1,685)	(1,665)	(1,570)	(1,571)	(1,685)	(1,570)
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	32,003	(3,029)	(36,412)	(24,874)	(3,029)	(24,874)
Ending balance	$ 20,437	$ 32,003	$ (17,286)	$ (36,412)	$ 20,437	$ (17,286)