Contract Balances (Tables)

12 Months Ended

Dec. 31, 2021

Revenue Recognition and Deferred Revenue [Abstract]

Allowance for Doubtful Accounts

The following table presents the changes in the allowance for doubtful accounts for the periods presented (in thousands):

	Year Ended December 31,
	2021		2020		2019
Allowance for doubtful accounts:
Balance, beginning of period	$	3,427	$	4,522	$	4,838
Additions charged to expense	1,073		2,650		2,772
Less: write-offs, net of recoveries and other adjustments	(742)		(3,745)		(3,088)
Balance, end of period	$	3,758	$	3,427	$	4,522