Income Taxes - Schedule of Net Operating Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Total	$ 290,492	$ 192,154	$ 84,808
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	189,284	122,824	66,906
Tax credit carryforwards	6,630	3,312	2,070
California
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	9,512	6,251	3,144
Other States
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	80,808	57,494	11,396
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	90,300
Tax credit carryforwards	$ 4,258	$ 2,273	$ 1,292