Income Before Income Tax (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Income Before Income Tax [Line Items]
U.S.									$ 16,453	$ 3,577	$ 12,359
Foreign									223,475	150,859	121,302
Income before income taxes	$ 64,004	$ 65,747	$ 57,382	$ 52,795	$ 55,514	$ 31,687	$ 34,927	$ 32,308	$ 239,928	$ 154,436	$ 133,661