CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 19,528	$ 23,141	$ 58,225	$ 59,068
Other comprehensive income (loss):
Currency translation adjustment, gross	(7,600)	(1,996)	(7,120)	(2,632)
Tax (expense) benefit	2,660	102	2,492	410
Comprehensive income	$ 14,588	$ 21,247	$ 53,597	$ 56,846