Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred income tax assets:
Accounts payable and accrued expenses	$ 10,786	$ 9,899
163(j) interest limitation	10,693	6,903
Deferred revenue	159	88
Allowance for doubtful accounts	83	92
Property, plant and equipment, net	396	1,044
Intangibles	125	95
Investments	60,185	58,779
Stock-based compensation	1,612	713
Other	0	59
Operating lease liabilities	2,249	2,565
Research and development tax credits	5,533	0
Net operating loss carryforwards	119,486	110,536
Less: Valuation allowance	(187,075)	(163,719)
Total deferred income tax assets	24,232	27,054
Deferred income tax liabilities:
State taxes	(7,867)	(6,750)
Intangible assets, net	(15,535)	(17,446)
Convertible notes	0	(1,549)
Deferred costs to obtain a customer contract	(226)	(351)
Capitalized labor costs	(344)	(520)
Other	(361)	(394)
Operating lease right-of-use assets	(1,674)	(1,897)
Total deferred income tax liabilities	(26,007)	(28,907)
Deferred income taxes, net	$ (1,775)	$ (1,853)