Stock-Based Compensation Expense Included in Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 40,926	$ 19,789	$ 31,154
Stock-based compensation expense, included in restructuring expense	47	116	4,283
Total stock-based compensation cost	40,973	19,905	35,437
Income tax (benefit)	(6,877)	(2,784)	(6,937)
Total stock-based compensation cost, net of tax	34,096	17,121	28,500
SG&A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 40,926	$ 19,789	$ 31,154