CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (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 Income And Comprehensive Income [Abstract]
Net income	$ 7,311	$ 7,415	$ 15,927	$ 13,135
Other comprehensive (loss) income, net of tax:
Unrecognized actuarial gain	11		11
Foreign currency translation adjustments	363	(1,262)	(680)	(712)
Comprehensive income	$ 7,685	$ 6,153	$ 15,258	$ 12,423