Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued compensation	$ 9,282	$ 4,102
Operating lease liabilities, current	2,354
Accrued in process research and development	1,600
Accrued consulting fees	1,337	665
Accrued other	1,126	769
Accrued legal fees	837	1,310
Accrued accounting fees	173	722
Total accrued expenses	$ 16,709	$ 7,568