Income Taxes - Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Income tax benefit at U.S. federal statutory rate	21.00%	21.00%
State income tax benefit, net of federal benefit	3.90%
Other permanent differences	(14.90%)	(0.40%)
Goodwill impairment		(7.60%)
Research and development credit	(0.20%)	0.90%
Change in state tax rate		(1.10%)
Foreign rate differential	(0.10%)
Other adjustments	0.30%
Change in valuation allowance	(8.80%)	(3.90%)
Effective income tax rate	1.20%	8.90%