Income (loss) before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2013		May 31, 2012		May 31, 2011
Schedule of Income Before Income Tax [Line Items]
Income Before Income Taxes, United States	$ 5,104		$ 187,687		$ 217,427
Income Before Income Taxes, Foreign	171,787		140,602		77,626
Income (Loss) Before Income Taxes	$ 176,891	[1]	$ 328,289	[1]	$ 295,053	[1]

[1] The presentation includes a reconciliation of Income (Loss) Before Income Taxes, a measure defined by Generally Accepted Accounting Principles (GAAP) in the United States, to EBIT.