Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 300	$ 200	$ 0
Domestic Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	242,600
Operating loss carryforwards, not subject to expiration	188,500
Unrecognized tax benefits	200
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	54,100
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Operating loss carryforwards	237,500
Foreign Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	70,800
Unrecognized tax benefits	100
Research Tax Credit Carryforward | Domestic Tax Authority
Income Tax Contingency [Line Items]
Tax credit carryforward, amount	3,700
Research Tax Credit Carryforward | State and Local Jurisdiction
Income Tax Contingency [Line Items]
Tax credit carryforward, amount	$ 900