CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 23,802	$ 22,974	$ 16,570
Unrealized gain on marketable securities:
Interest rate swap	(571)	(630)	2,992
Less income tax benefit (expense)	222	245	(1,164)
Foreign currency translation adjustment	(3,037)	(3,160)	292
Less income tax benefit	311	190	5
Total other comprehensive income (loss)	(3,075)	(3,355)	2,125
Total comprehensive income	$ 20,727	$ 19,619	$ 18,695