Schedule of Combined Financial Information for Unconsolidated Affiliates (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Feb. 28, 2014
Feb. 28, 2013
Feb. 28, 2014
Feb. 28, 2013
May 31, 2013
Investments in and Advances to Affiliates [Line Items]          
Cash $ 56,077   $ 56,077   $ 70,380
Receivable from partner 12,897 [1]   12,897 [1]   69,706 [1]
Other current assets 437,179   437,179   518,262
Noncurrent assets 296,033   296,033   350,681
Total assets 802,186   802,186   1,009,029
Current liabilities 136,419   136,419   181,111
Short-term borrowings 38,204   38,204   21,369
Current maturities of long-term debt 4,782   4,782   5,442
Long-term debt 269,461   269,461   274,750
Other noncurrent liabilities 18,105   18,105   18,345
Equity 335,215   335,215   508,012
Total liabilities and equity 802,186   802,186   1,009,029
Net sales 340,645 421,645 1,121,362 1,306,758  
Gross margin 73,217 90,570 239,098 254,796  
Operating income 48,752 61,387 164,824 169,997  
Depreciation and amortization 8,622 9,979 28,063 29,089  
Interest expense 2,494 2,212 6,950 6,681  
Income tax expense 2,937 1,842 8,829 5,488  
Net earnings $ 44,018 $ 57,421 $ 149,801 $ 158,570  
[1] Represents cash owed from a joint venture partner as a result of centralized cash management.