Consolidated Statements Of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010
Consolidated Statements Of Earnings [Abstract]
Net sales	$ 565,652	$ 580,687	$ 1,168,039	$ 1,197,492
Cost of goods sold	509,046	510,868	1,039,971	1,048,759
Gross margin	56,606	69,819	128,068	148,733
Selling, general and administrative expense	52,901	56,971	98,262	113,749
Restructuring and other expense (income)	2,048	(76)	3,751	988
Joint venture transactions	(1,192)		2,023
Operating income	2,849	12,924	24,032	33,996
Other income (expense):
Miscellaneous income (expense)	279	(94)	680	(137)
Interest expense	(4,756)	(4,838)	(9,444)	(9,546)
Equity in net income of unconsolidated affiliates	21,912	16,223	46,609	34,512
Earnings before income taxes	20,284	24,215	61,877	58,825
Income tax expense	6,083	7,332	19,336	17,689
Net earnings	14,201	16,883	42,541	41,136
Net earnings attributable to noncontrolling interest	2,216	2,414	4,904	4,313
Net earnings attributable to controlling interest	$ 11,985	$ 14,469	$ 37,637	$ 36,823
Basic
Average common shares outstanding	69,350	74,062	70,440	75,870
Earnings per share attributable to controlling interest	$ 0.17	$ 0.20	$ 0.53	$ 0.49
Diluted
Average common shares outstanding	69,356	74,077	70,925	75,882
Earnings per share attributable to controlling interest	$ 0.17	$ 0.20	$ 0.53	$ 0.49
Common shares outstanding at end of period	68,937	74,108	68,937	74,108
Cash dividends declared per share	$ 0.12	$ 0.10	$ 0.24	$ 0.20