Consolidated Statements Of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2012	Nov. 30, 2011
Net sales	$ 622,622	$ 565,652	$ 1,288,657	$ 1,168,039
Cost of goods sold	527,766	509,046	1,100,150	1,039,971
Gross margin	94,856	56,606	188,507	128,068
Selling, general and administrative expense	65,101	52,901	124,523	98,262
Impairment of long-lived assets	(50)		1,520
Restructuring and other expense	1,262	2,048	1,665	3,751
Joint venture transactions	(279)	(1,192)	(1,441)	2,023
Operating income	28,822	2,849	62,240	24,032
Other income (expense):
Miscellaneous income	303	279	468	680
Interest expense	(6,334)	(4,756)	(11,593)	(9,444)
Equity in net income of unconsolidated affiliates	25,221	21,912	47,864	46,609
Earnings before income taxes	48,012	20,284	98,979	61,877
Income tax expense	15,390	6,083	31,492	19,336
Net earnings	32,622	14,201	67,487	42,541
Net earnings attributable to noncontrolling interest	796	2,216	1,699	4,904
Net earnings attributable to controlling interest	$ 31,826	$ 11,985	$ 65,788	$ 37,637
Basic
Average common shares outstanding	68,934	69,350	68,604	70,440
Earnings per share attributable to controlling interest	$ 0.46	$ 0.17	$ 0.96	$ 0.53
Diluted
Average common shares outstanding	70,411	69,356	69,834	70,925
Earnings per share attributable to controlling interest	$ 0.45	$ 0.17	$ 0.94	$ 0.53
Common shares outstanding at end of period	69,060	68,937	69,060	68,937
Cash dividends declared per share	$ 0.13	$ 0.12	$ 0.26	$ 0.24