Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 105,508	$ 76,080	$ 39,939
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of ($5), $6 and ($4) for the years ended December 31, 2019, 2018 and 2017	14	(17)	12
Unrealized gain (loss) on available-for-sale securities, net of tax of $111 and $100 for the years ended December 31, 2018 and 2017, respectively	0	(292)	(388)
Other comprehensive income (loss)	14	(309)	(376)
Comprehensive income (loss)	105,522	75,771	39,563
Comprehensive (income) loss attributable to noncontrolling interests	(9,859)	(551)	(2,927)
Comprehensive income (loss) attributable to stockholders	$ 95,663	$ 75,220	$ 36,636