Consolidated Statements Of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Consolidated Statements Of Earnings [Abstract]
Net sales	$ 611,255	$ 569,439	$ 1,779,294	$ 1,766,931
Cost of goods sold	527,923	481,185	1,567,894	1,529,944
Gross margin	83,332	88,254	211,400	236,987
Selling, general and administrative expense	62,489	59,769	160,751	173,518
Restructuring and other expense	956	464	4,707	1,452
Joint venture transactions	1,812		3,835
Operating income	18,075	28,021	42,107	62,017
Other income (expense):
Miscellaneous income (expense)	728	(219)	1,408	(356)
Interest expense	(5,073)	(4,533)	(14,517)	(14,079)
Equity in net income of unconsolidated affiliates	24,005	16,958	70,614	51,470
Earnings before income taxes	37,735	40,227	99,612	99,052
Income tax expense	9,337	11,893	28,673	29,582
Net earnings	28,398	28,334	70,939	69,470
Net earnings attributable to noncontrolling interest	2,518	2,008	7,422	6,321
Net earnings attributable to controlling interest	$ 25,880	$ 26,326	$ 63,517	$ 63,149
Basic
Average common shares outstanding	68,972	74,171	69,952	75,306
Earnings per share attributable to controlling interest	$ 0.38	$ 0.35	$ 0.91	$ 0.84
Diluted
Average common shares outstanding	69,509	75,001	70,481	75,687
Earnings per share attributable to controlling interest	$ 0.37	$ 0.35	$ 0.90	$ 0.83
Common shares outstanding at end of period	69,014	74,195	69,014	74,195
Cash dividends declared per share	$ 0.12	$ 0.10	$ 0.36	$ 0.30