Summary of Significant Accounting Policies - Summary of Allowance for Doubtful Accounts Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Allowance for doubtful accounts, Beginning Balance	$ 1,883	$ 1,883
Provision for doubtful accounts	1,343	1,013	$ 581
Write-offs, net of recoveries	(1,126)	(1,013)
Allowance for doubtful accounts, Ending Balance	$ 2,100	$ 1,883	$ 1,883