Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 34,073	$ 33,178
Restricted cash, included in other current assets	$ 934	$ 819
Restricted cash, current, asset, statement of financial position [extensible list]	us-gaap:OtherAssetsCurrent	us-gaap:OtherAssetsCurrent
Total cash, cash equivalents and restricted cash	$ 35,007	$ 33,997	$ 69,378	$ 19,623