Income Taxes - Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax (benefit) expense at the statutory rate	$ 4,057	$ 12,309	$ 2,681
Provision to return and deferred tax adjustments	(2,857)	157	1,017
U.S. state tax, net of federal benefit	1,615	3,095	637
Permanent adjustments	107	606	738
Tax rates (less than) in excess of statutory tax rates	(1,164)	1,143	2,247
Impact of finance structure	(1,070)	(4,434)	354
Non-deductible/(non-taxable) transaction costs	1,636	(3,816)	(425)
Goodwill impairment (non-deductible)	0	1,941	0
U.S. Tax Reform (net impact)	0	764	(435)
Tax law changes	(9,665)	0	0
Share-based compensation	1,702	2,223	2,107
Capital gains	0	0	851
Other	(128)	499	48
Subtotal	(5,767)	14,487	9,820
Change in valuation allowance	6,219	2,035	637
Total income tax expense	$ 452	$ 16,522	$ 10,457