Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Cash and cash equivalents	$ 146,261	$ 89,893	$ 34,234
Short-term restricted cash	0		279
Long-term restricted cash	1,379		1,379
Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows	$ 147,640	$ 91,551	$ 35,892	$ 37,682