Investments In Unconsolidated Affiliates (Schedule Of Combined Financial Information For Unconsolidated Affiliates) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010	May 31, 2011
Investments In Unconsolidated Affiliates [Abstract]
Cash	$ 161,622		$ 161,622		$ 122,938
Other current assets	494,035		494,035		474,284
Noncurrent assets	332,356		332,356		260,805
Total assets	988,013		988,013		858,027
Current maturities of long-term debt	3,615		3,615
Current liabilities	206,583		206,583		184,467
Long-term debt	180,161		180,161		150,229
Other noncurrent liabilities	21,244		21,244		5,365
Equity	576,410		576,410		517,966
Total liabilities and equity	988,013		988,013		858,027
Net sales	420,103	210,666	848,204	423,805
Gross margin	79,985	49,856	163,809	105,198
Depreciation and amortization	4,766	2,767	9,602	5,562
Interest expense	950	373	1,826	783
Income tax expense	5,766	2,429	10,124	5,521
Net earnings	$ 47,959	$ 33,224	$ 99,823	$ 70,647