Equity - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2018	Mar. 20, 2019	Sep. 27, 2017
Class of Stock [Line Items]
Stock repurchase program additional number of shares authorized to be repurchased				6,600,000
Common Stock remaining shares authorized for repurchase	7,700,000
Repurchase of common shares	$ 50,972	$ 168,113	$ 204,267
Repurchases and retirement of common shares (in shares)	1,300,000	4,100,000	4,375,000
Deferred compensation obligation credited to common share option	$ 547	$ 680	$ 1,218
Maximum | Stock repurchase on September 27, 2017
Class of Stock [Line Items]
Common Stock shares authorized for repurchase					6,828,855