Goodwill, Service Contracts and Other Assets - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Goodwill, Service Contracts and Other Assets [Abstract]
Amortization expense for service contracts and other assets	$ 35,700	$ 33,700	$ 105,600	$ 99,900
2020 (remaining three months)	34,641		34,641
2021	129,941		129,941
2022	118,066		118,066
2023	98,914		98,914
2024	87,387		87,387
Thereafter	297,951		297,951
Total future amortization expense	$ 766,900		$ 766,900