Income Taxes - Benefit (Provision) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax benefit (provision):
Federal	$ 16,615	$ 13,869	$ 22,255
State	5,802	2,170	6,406
Foreign			913
Expiration of NOLs and R&D Credit	(20,294)	(18,966)
Income tax benefit (provision) before valuation allowance	2,123	(2,927)	29,574
Deferred tax valuation allowance	(956)	$ 2,927	(28,809)
Income tax benefit (provision)	$ 1,167		$ 765