Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Income Statement [Abstract]
Net sales	$ 827,637	$ 958,226	$ 1,683,496	$ 1,946,333
Cost of goods sold	707,026	837,292	1,445,594	1,682,402
Gross margin	120,611	120,934	237,902	263,931
Selling, general and administrative expense	88,543	84,668	179,366	175,309
Impairment of long-lived assets	0	0	40,601	2,381
Restructuring and other expense (income), net	(50)	402	405	(534)
Operating income	32,118	35,864	17,530	86,775
Other income (expense):
Miscellaneous income, net	636	1,432	1,331	1,697
Interest expense	(7,315)	(9,472)	(16,795)	(19,200)
Loss on extinguishment of debt	0	0	(4,034)	0
Equity in net income of unconsolidated affiliates	47,346	21,087	72,113	51,095
Earnings before income taxes	72,785	48,911	70,145	120,367
Income tax expense	15,863	11,119	15,678	25,617
Net earnings	56,922	37,792	54,467	94,750
Net earnings attributable to noncontrolling interests	4,836	3,790	7,157	5,806
Net earnings attributable to controlling interest	$ 52,086	$ 34,002	$ 47,310	$ 88,944
Basic
Average common shares outstanding	55,059	57,716	55,150	58,226
Earnings per share attributable to controlling interest	$ 0.95	$ 0.59	$ 0.86	$ 1.53
Diluted
Average common shares outstanding	56,072	59,338	56,205	60,013
Earnings per share attributable to controlling interest	$ 0.93	$ 0.57	$ 0.84	$ 1.48
Common shares outstanding at end of period	55,094	56,957	55,094	56,957
Cash dividends declared per share	$ 0.24	$ 0.23	$ 0.48	$ 0.46