Accounts receivable

12 Months Ended

Dec. 31, 2021

Receivables [Abstract]

Accounts receivable

2. Accounts receivable

The following sets forth activities in our allowance for credit losses (in thousands):

	2021			2020			2019
Balance as of beginning of period	$	1,118		$	904		$	597
Charges to provision for credit losses		533			238			318
Write-off of uncollectible receivables		(317	)		(24	)		(11	)
Balance as of end of period	$	1,334		$	1,118		$	904