Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Differences between total income tax expense and amount computed using the statutory federal income tax rate
Income tax expense at federal statutory rate									$ (8,501)	$ 4,569	$ 7,063
State income taxes, net of federal income tax benefit									(1,632)	1,285	3,407
State contingencies added									1,519	944	2,287
Tax contingencies reversed due to statute closings									(1,762)	(2,860)	(2,500)
Change in valuation allowances									(924)	584	(691)
Share-based compensation									2,982	1,715	(4,750)
Qualified research credit									(2,424)	(1,418)	(1,584)
Non-deductible executive compensation									2,717	3,153	3,052
Non-deductible HIF fees									3,263		3,236
Sale of MCC Business									(39,819)
Other-net									50	1,190	1,937
Total income tax expense	$ (11,635)	$ (2,330)	$ (36,328)	$ 5,762	$ 5,854	$ 782	$ 5,735	$ (3,209)	$ (44,531)	$ 9,162	$ 11,457