Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net (Loss) Income	$ (3,703)	$ 36,995	$ 25,034	$ 78,554
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of ($28) and $56 for the three months ended September 30, 2015 and 2014, respectively and $167 and $49 for the nine months ended September 30, 2015 and 2014, respectively	49	(93)	(271)	(80)
Unrealized (loss) gain on available-for-sale securities, net of tax of ($35) and $60 for the three months ended September 30, 2015 and 2014, respectively and $26 and $(55) for the nine months ended September 30, 2015 and 2014, respectively	(290)	(95)	(389)	90
Other comprehensive (loss) income	(241)	(188)	(660)	10
Comprehensive (loss) income	(3,944)	36,807	24,374	78,564
Comprehensive loss attributable to noncontrolling interests	3,054	345	3,436	267
Comprehensive (Loss) Income Attributable to Common Stockholders	$ (890)	$ 37,152	$ 27,810	$ 78,831