Income Taxes - Summary of Operating Loss Carryforwards and Tax Credits (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Federal | Indefinite
Operating Loss Carryforwards [Line Items]
Net operating losses carryforwards	$ 59,014
Federal | 2037
Operating Loss Carryforwards [Line Items]
Net operating losses carryforwards	2
Federal | 2037-2038
Operating Loss Carryforwards [Line Items]
Tax credits	1,180
State | Indefinite
Operating Loss Carryforwards [Line Items]
Tax credits	1,120
State | 2037-2038
Operating Loss Carryforwards [Line Items]
Net operating losses carryforwards	$ 57,895