Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 21,183	$ 43,352
Tax credit carryforwards	9,022	4,152
Accrued expenses	19,572	9,946
Allowance for bad debt	4,366	2,547
Share-based compensation expense	5,923	4,669
Impairment of investments	6,762	1,675
Deferred revenue	1,334	0
State taxes	5,124	3,206
Other	12,045	9,958
Deferred tax assets, gross	85,331	79,505
Less: valuation allowance	(8,307)	(608)
Total deferred tax assets	77,024	78,897
Deferred tax liabilities:
Basis difference in property and equipment	(18,995)	(15,767)
Basis difference in intangible assets	(93,162)	(42,880)
Prepaid insurance	(2,905)	(1,847)
Convertible debt	(65,192)	(65,217)
Other	(2,925)	(663)
Total deferred tax liabilities	(183,179)	(126,374)
Net deferred tax liabilities	$ (106,155)	$ (47,477)