Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 119,963	$ 105,508	$ 76,080
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of $(7), $(5) and $6 for the years ended December 31, 2020, 2019 and 2018	20	14	(17)
Unrealized gain (loss) on available-for-sale securities, net of tax of $111 for the year ended December 31, 2018	0	0	(292)
Other comprehensive income (loss)	20	14	(309)
Comprehensive income (loss)	119,983	105,522	75,771
Comprehensive (income) loss attributable to noncontrolling interests	(40,006)	(9,859)	(551)
Comprehensive income (loss) attributable to stockholders	$ 79,977	$ 95,663	$ 75,220