Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 200,850	$ 217,937	$ 157,628
Other comprehensive income (loss):
Foreign currency translation	12,744	1,342	4,716
Pension liability adjustment, net of tax	1,566	2,242	(2,058)
Cash flow hedges, net of tax	959	(2,822)	22,208
Other comprehensive income	15,269	762	24,866
Comprehensive income	216,119	218,699	182,494
Comprehensive income attributable to noncontrolling interests	6,429	13,394	16,640
Comprehensive income attributable to controlling interest	$ 209,690	$ 205,305	$ 165,854