Income Taxes - Operating Loss Carryforwards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Federal
Operating Loss Carryforwards
Operating loss carryforward	$ 135,890
Research tax credits	3,770
State
Operating Loss Carryforwards
Operating loss carryforward	117,579
Research tax credits	645
Foreign
Operating Loss Carryforwards
Operating loss carryforward	83,950
Indefinite federal net operating loss carryforward	$ 54,581