Provision for Income Taxes - Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax at U.S. statutory rate	21.00%	21.00%	21.00%
Increase in deferred tax valuation allowance	(30.20%)	(35.80%)	(50.60%)
Stock compensation	14.50%	11.40%	20.70%
Acquisitions	(0.20%)	(0.60%)	15.80%
R&D credit	0.00%	0.10%	4.80%
State taxes, net of federal benefit	3.90%	4.60%	7.10%
Change in uncertain tax positions	(2.20%)	0.00%	0.00%
Executive compensation	(7.40%)	(2.50%)	(3.30%)
Other permanent items	(0.90%)	0.90%	(0.40%)
Income tax benefit (provision) effective rate	(1.50%)	(0.90%)	15.10%