Basis of Presentation and Summary of Significant Accounting Policies - Summary of Adoption ASC 842 (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
Other current liabilities	132	104	$ 165
Operating lease liability, net of current portion	16,889	19,790
Other non-current liabilities	0	0	2,062
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
Other current liabilities		(61)
Operating lease liability, net of current portion		19,790
Other non-current liabilities		(2,062)
Accumulated deficit		$ (75)