Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 28,393	$ 21,134
Tax credit carryforwards	2,801	9,022
Accrued expenses	12,548	17,393
Allowance for bad debt	2,116	3,757
Share-based compensation expense	3,545	5,923
Impairment of investments	0	6,714
Deferred revenue	4,331	912
State taxes	3,771	4,948
Other	9,426	11,071
Deferred tax assets, gross	66,931	80,874
Less: valuation allowance	(1,812)	(8,262)
Total deferred tax assets	65,119	72,612
Deferred tax liabilities:
Basis difference in property and equipment	(8,337)	(17,126)
Basis difference in intangible assets	(117,244)	(129,301)
Unrealized gains on investments	(11,291)	0
Prepaid insurance	(3,121)	(2,703)
Convertible debt	(21,972)	(65,192)
Other	(6,219)	(3,403)
Total deferred tax liabilities	(168,184)	(217,725)
Net deferred tax liabilities	$ (103,065)	$ (145,113)