Investments In Unconsolidated Affiliates (Schedule Of Combined Financial Information For Unconsolidated Affiliates) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011	May 31, 2011
Investments In Unconsolidated Affiliates [Abstract]
Cash	$ 119,921		$ 119,921		$ 122,938
Other current assets	503,692		503,692		474,284
Noncurrent assets	338,098		338,098		260,805
Total assets	961,711		961,711		858,027
Current maturities of long-term debt	3,632		3,632
Current liabilities	170,285		170,285		184,467
Long-term debt	247,115		247,115		150,229
Other noncurrent liabilities	57,183		57,183		5,365
Equity	483,496		483,496		517,966
Total liabilities and equity	961,711		961,711		858,027
Net sales	409,981	201,678	1,258,185	625,483
Gross margin	82,904	50,797	246,714	155,995
Depreciation and amortization	4,171	2,840	13,773	8,402
Interest expense	1,925	364	3,751	1,147
Income tax expense	1,908	1,504	12,032	7,025
Net earnings	$ 51,955	$ 31,442	$ 151,779	$ 102,089