v3.19.3.a.u2
Summary of Significant Accounting Policies - Summary of Changes in the Allowance for Doubtful Accounts (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]      
Balance as of January 1 $ 2,086 $ 742 $ 323
Provision for doubtful accounts 441 1,521 419
Write-offs $ (2,527) (177)  
Balance as of December 31   $ 2,086 $ 742