Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
Income Statement [Abstract]
Net sales	$ 958,226	$ 871,266	$ 1,946,333	$ 1,719,503
Cost of goods sold	837,292	731,187	1,682,402	1,446,646
Gross margin	120,934	140,079	263,931	272,857
Selling, general and administrative expense	84,668	89,425	175,309	177,674
Impairment of goodwill and long-lived assets		8,289	2,381	8,289
Restructuring and other expense (income), net	402	(9,694)	(534)	(7,390)
Operating income	35,864	52,059	86,775	94,284
Other income (expense):
Miscellaneous income, net	1,432	1,321	1,697	1,669
Interest expense	(9,472)	(10,038)	(19,200)	(18,845)
Equity in net income of unconsolidated affiliates	21,087	16,445	51,095	43,751
Earnings before income taxes	48,911	59,787	120,367	120,859
Income tax expense	11,119	18,165	25,617	31,163
Net earnings	37,792	41,622	94,750	89,696
Net earnings attributable to noncontrolling interests	3,790	2,219	5,806	4,759
Net earnings attributable to controlling interest	$ 34,002	$ 39,403	$ 88,944	$ 84,937
Basic
Average common shares outstanding	57,716	61,503	58,226	61,976
Earnings per share attributable to controlling interest	$ 0.59	$ 0.64	$ 1.53	$ 1.37
Diluted
Average common shares outstanding	59,338	63,468	60,013	64,044
Earnings per share attributable to controlling interest	$ 0.57	$ 0.62	$ 1.48	$ 1.33
Common shares outstanding at end of period	56,957	60,755	56,957	60,755
Cash dividends declared per share	$ 0.23	$ 0.21	$ 0.46	$ 0.42