Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use asset	$ 17,615	$ 20,156
Operating lease liability, current	2,901	2,563
Operating lease liability, net of current portion	16,889	19,790
Accumulated deficit	$ 107,159	163,982	$ 163,907
ASC 842
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use asset		20,156
Operating lease liability, current		2,563
Operating lease liability, net of current portion		19,790
Accumulated deficit		$ 75