Reconciliation of Income Tax Expense (Benefit) Computed by Applying U.S. Statutory Federal Income Tax Rate against Income (Loss) before Income Taxes to Provision (Benefit) for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
May 31, 2013	May 31, 2012	May 31, 2011
Income Tax Rate Reconciliation [Line Items]
Income tax expense (benefit) at the U.S. statutory federal income tax rate	$ 61,912	$ 114,901	$ 103,141
Impact of foreign operations	(11,552)	(32,192)	(39,932)
State and local income taxes net of federal income tax benefit	1,979	4,073	4,527
Tax benefits from the domestic manufacturing deduction	(4,489)	(3,744)	(2,750)
Nondeductible fines and penalties	4,802
Nondeductible business expense	1,269	1,304	1,404
Valuation allowance	14,729	9,353	24,994
Other	(1,610)	831	501
Provision (Benefit) for Income Tax Expense	$ 67,040	$ 94,526	$ 91,885
Effective Income Tax Rate	37.90%	28.80%	31.10%

Reconciliation of Income Tax Expense (Benefit) Computed by Applying U.S. Statutory Federal Income Tax Rate against Income (Loss) before Income Taxes to Provision (Benefit) for Income Taxes (Detail) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

May 31, 2013

May 31, 2012

May 31, 2011

Income Tax Rate Reconciliation [Line Items]

Income tax expense (benefit) at the U.S. statutory federal income tax rate

$ 61,912

$ 114,901

$ 103,141

Impact of foreign operations

(11,552)

(32,192)

(39,932)

State and local income taxes net of federal income tax benefit

1,979

4,073

4,527

Tax benefits from the domestic manufacturing deduction

(4,489)

(3,744)

(2,750)

Nondeductible fines and penalties

4,802

Nondeductible business expense

1,269

1,304

1,404

Valuation allowance

14,729

9,353

24,994

Other

(1,610)

831

501

Provision (Benefit) for Income Tax Expense

$ 67,040

$ 94,526

$ 91,885

Effective Income Tax Rate

37.90%

28.80%

31.10%

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