Earnings Per Share - Computation of Basic and Diluted Earnings Per Share Attributable to Controlling Interest (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Aug. 31, 2018	Aug. 31, 2017
Numerator (basic & diluted):
Net earnings attributable to controlling interest - income available to common shareholders	$ 54,942	$ 45,534
Denominator:
Denominator for basic earnings per share attributable to controlling interest-weighted average common shares	58,731	62,444
Effect of dilutive securities	1,890	2,146
Denominator for diluted earnings per share attributable to controlling interest-adjusted weighted average common shares	60,621	64,590
Basic earnings per share attributable to controlling interest	$ 0.94	$ 0.73
Diluted earnings per share attributable to controlling interest	$ 0.91	$ 0.70