Schedule Of Combined Financial Information for Unconsolidated Affiliates (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2012	May 31, 2011
Investments in and Advances to Affiliates [Line Items]
Current assets	$ 626,975	$ 597,222
Noncurrent assets	345,500	260,805
Total assets	972,475	858,027
Current liabilities	174,016	184,467
Current maturities of long-term debt	5,305
Long-term debt	289,308	150,229
Other noncurrent liabilities	21,934	5,365
Equity	481,912	517,966
Total liabilities and equity	$ 972,475	$ 858,027