Revenue From Contracts With Customers - Summary of Allowance for Accounts Receivable (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	$ 19
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Provision for credit losses	9	$ 28
Write-offs		(20)
Ending balance	$ 28	23
Cumulative Effect, Period of Adoption, Adjustment
Accounts Notes And Loans Receivable [Line Items]
Beginning balance		$ 15