Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 13,024	$ 26,296	$ 21,991
Other comprehensive income (loss), net of taxes:
Foreign currency translation	826	7,419	(1,335)
Net change in market value of investments	1,040	(3)	(21)
Other comprehensive income (loss)	1,866	7,416	(1,356)
Comprehensive income	$ 14,890	$ 33,712	$ 20,635