Schedule of Income Before Income Tax (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Income Before Income Tax [Line Items]
U.S.									$ 23,966	$ 26,815	$ 16,453
Foreign									294,907	259,007	223,475
Income before income taxes	$ 89,265	$ 78,619	$ 75,402	$ 75,587	$ 85,161	$ 76,217	$ 63,556	$ 60,888	$ 318,873	$ 285,822	$ 239,928