Leases - Operating Lease Cost and Additional Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020	May 31, 2020
Leases [Abstract]
Operating lease costs	$ 17,700	$ 18,000	$ 52,900	$ 52,900
Other information related to operating leases
Cash paid for amounts included in the measurement of operating lease liabilities			36,654	38,292
Operating lease right-of-use assets obtained in exchange for new and renewed operating lease liabilities			$ 27,771	$ 33,382
Weighted-average remaining lease term - operating leases	5 years		5 years		5 years 2 months 8 days
Weighted-average discount rate - operating leases	2.46%		2.46%		2.66%