Unearned Revenue

6 Months Ended

Jun. 30, 2020

Unearned Revenue

Unearned revenue

14.Unearned Revenue

Changes in unearned revenue were as follows for the three and six months ended June 30, 2020 and 2019:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(in thousands)	2020		2019		2020		2019
Balance, beginning of period	$	114,038	$	102,879	$	118,211	$	105,837
Billings, excluding billings for customer arrangements with termination rights		53,047		49,477		93,838		89,800
Additions to unearned revenue upon expiration of termination rights		4,599		5,062		9,244		10,062
Recognition of revenue, net of change in unbilled accounts receivable*		(58,746)		(51,019)		(108,355)		(99,300)
Acquired unearned revenue		275		—		275		—
Balance, end of period	$	113,213	$	106,399	$	113,213	$	106,399
* Reconciliation to Revenue Reported per Condensed Consolidated Statement of Operations:	Three Months Ended				Six Months Ended
	June 30,				June 30,
(in thousands)	2020		2019		2020		2019
Revenue billed as of the end of period	$	58,746	$	51,019	$	108,355	$	99,300
Increase (decrease) in total unbilled accounts receivable		179		(154)		268		(353)
Revenue Reported in Condensed Consolidated Statement of Operations	$	58,925	$	50,865	$	108,623	$	98,947

Revenue allocated to remaining performance obligations includes unearned revenue plus contractually committed amounts that will be invoiced and recognized as revenue in future periods, but excludes amounts invoiced and not recognized as revenue under customer arrangements that contain termination rights. Remaining performance obligations were $126.0 million as of June 30, 2020, of which we expect to recognize approximately 74% as revenue over the next 12 months and the remainder thereafter.

As of June 30, 2020 and December 31, 2019, the balance of customer arrangements that contain termination rights was $12.1 million and $16.1 million, respectively.