Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 8,700	$ 9,012	$ 20,570	$ 28,737
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of ($287) and $30 for the three months ended June 30, 2016 and 2015, respectively and ($348) and $195 for the six months ended June 30, 2016 and 2015, respectively	470	(49)	569	(320)
Unrealized gain (loss) on available-for-sale securities, net of tax of ($74) and $62 for the three months ended June 30, 2016 and 2015, respectively and ($171) and $61 for the six months ended June 30, 2016 and 2015 respectively	121	(103)	281	(99)
Other comprehensive income (loss)	591	(152)	850	(419)
Comprehensive income	9,291	8,860	21,420	28,318
Comprehensive income (loss) attributable to noncontrolling interests	(612)	765	(119)	382
Comprehensive Income Attributable to Common Stockholders	$ 8,679	$ 9,625	$ 21,301	$ 28,700