Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2018
Accounting Policies [Abstract]
Interest paid, net of amount capitalized	$ 32,994	$ 38,807	$ 34,839
Income taxes paid, net of refunds	$ 25,076	$ 38,848	$ 44,819