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	$ 30,671	$ 96,965	$ 77,130
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of $266, $132 and ($50) for the years ended December 31, 2015, 2014 and 2013, respectively	(434)	(216)	81
Unrealized (loss) gain on available-for-sale securities, net of tax of $71, ($76), and $223 for the years ended December 31, 2015, 2014 and 2013, respectively	(358)	124	56
Other comprehensive (loss) income	(792)	(92)	137
Comprehensive income	29,879	96,873	77,267
Comprehensive income (loss) attributable to noncontrolling interests	4,435	735	(1,940)
Comprehensive income attributable to common stockholders	$ 34,314	$ 97,608	$ 75,327