Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 13,542	$ 18,067	$ 30,886	$ 33,752
Other comprehensive income (loss):
Foreign currency translation adjustments	(3,578)	(7,705)	(4,096)	(3,378)
Total other comprehensive income (loss)	(3,578)	(7,705)	(4,096)	(3,378)
Comprehensive income	$ 9,964	$ 10,362	$ 26,790	$ 30,374