Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 115,374	$ 147,449	$ 62,741
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	117,808	$ 149,804	65,196	$ 107,099
Prepaid Expenses and Other Current Assets
Summary Of Significant Accounting Policies [Line Items]
Restricted cash, current	395		263
Other Assets
Summary Of Significant Accounting Policies [Line Items]
Restricted cash, noncurrent	$ 2,039		$ 2,192