Revenue (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Summary of Total Receivables, Net

Total receivables, net is comprised of the following (in thousands):

	December 31,
	2021		2020
Billed receivables	$	162,479	$	179,177
Allowance for doubtful accounts	(2,861)		(3,912)
Billed receivables, net	159,618		175,265
Current accrued receivables, net	160,787		167,614
Long-term accrued receivables, net	276,164		215,772
Total accrued receivables, net	436,951		383,386
Total receivables, net	$	596,569	$	558,651

Summary of Allowance for Doubtful Accounts Receivable

The following reflects activity in the Company’s allowance for doubtful accounts receivable for the periods indicated (in thousands):

	Years Ended December 31,
	2021		2020		2019
Balance, beginning of period	$	(3,912)	$	(5,149)	$	(3,912)
Provision (increase) decrease	1,125		374		(2,561)
Amounts written off, net of recoveries	(82)		941		1,368
Foreign currency translation adjustments and other	8		(78)		(44)
Balance, end of period	$	(2,861)	$	(3,912)	$	(5,149)

Summary of Changes in Deferred Revenue

Changes in deferred revenue were as follows (in thousands):

Balance, December 31, 2019	$	118,939
Deferral of revenue	149,363
Recognition of deferred revenue	(141,313)
Foreign currency translation	2,424
Balance, December 31, 2020	129,413
Deferral of revenue	154,419
Recognition of deferred revenue	(171,530)
Foreign currency translation	(1,952)
Balance, December 31, 2021	$	110,350