Unearned Revenue

9 Months Ended

Sep. 30, 2019

13.Unearned Revenue

Changes in unearned revenue were as follows for the three and nine months ended September 30, 2019 and 2018:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(in thousands)	2019		2018		2019		2018
Balance, beginning of period	$	106,399	$	82,934	$	105,837	$	77,022
Billings, excluding billings for customer arrangements with termination rights		46,246		55,819		135,904		144,107
Additions to unearned revenue upon expiration of termination rights		5,056		4,385		15,118		12,741
Recognition of revenue, net of change in unbilled accounts receivable*		(50,900)		(50,164)		(150,058)		(140,896)
Balance, end of period	$	106,801	$	92,974	$	106,801	$	92,974

* Reconciliation to Revenue Reported per Condensed Consolidated Statement of Operations:	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(in thousands)	2019		2018		2019		2018
Revenue billed as of the end of period	$	50,900	$	50,164	$	150,058	$	140,896
Increase (decrease) in total unbilled accounts receivable		1,301		(913)		1,090		(1,827)
Revenue Reported in Condensed Consolidated Statement of Operations	$	52,201	$	49,251	$	151,148	$	139,069

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 $117.4 million as of September 30, 2019, of which we expect to recognize approximately 72% as revenue over the next 12 months and the remainder thereafter.

As of September 30, 2019 and December 31, 2018, the balance of customer arrangements that contain termination rights was $16.2 million and $19.4 million, respectively.