Summary of Components of Income Before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
Income before income taxes	$ 202,184	$ 134,085	$ 115,526
U.S.
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
Income before income taxes	124,915	78,933	54,793
Non-U.S.
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
Income before income taxes	$ 77,269	$ 55,152	$ 60,733