Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	[1]	Feb. 29, 2016	[1]	Nov. 30, 2015	[1]	Aug. 31, 2015	[1]	May 31, 2017	May 31, 2016	May 31, 2015
Numerator (basic & diluted):
Net earnings attributable to controlling interest - income available to common shareholders	$ 56,494	$ 35,889	$ 46,565	$ 65,567	$ 58,523		$ 29,847		$ 23,376		$ 31,968		$ 204,515	$ 143,715	$ 76,785
Denominator:
Denominator for basic earnings per share attributable to controlling interest - weighted average common shares													62,443	62,469	66,309
Effect of dilutive securities													2,431	2,286	2,174
Denominator for diluted earnings per share attributable to controlling interest - adjusted weighted average common shares													64,874	64,755	68,483
Basic earnings per share attributable to controlling interest	$ 0.90	$ 0.57	$ 0.75	$ 1.06	$ 0.95		$ 0.48		$ 0.37		$ 0.50		$ 3.28	$ 2.30	$ 1.16
Diluted earnings per share attributable to controlling interest	$ 0.87	$ 0.55	$ 0.72	$ 1.02	$ 0.92		$ 0.47		$ 0.36		$ 0.48		$ 3.15	$ 2.22	$ 1.12

[1] Amounts are presented on a revised basis due to the adoption of amended accounting guidance related to the accounting for share-based payments in the fourth quarter of fiscal 2016. As a result of the adoption of this amended accounting guidance, net earnings and net earnings attributable to controlling interest for the three month periods ended August 31, 2015, November 30, 2015 and February 29, 2016 increased $558,000, $136,000 and $271,000, respectively, from the previously reported results.