Unearned Revenue (Tables)

3 Months Ended

Mar. 31, 2020

Unearned Revenue

Schedule of changes in unearned revenue

	Three Months Ended
	March 31,
(in thousands)	2020		2019
Balance, beginning of period	$	118,211	$	105,837
Billings, excluding billings for customer arrangements with termination rights		40,791		40,323
Additions to unearned revenue upon expiration of termination rights		4,645		5,000
Recognition of revenue, net of change in unbilled accounts receivable*		(49,609)		(48,281)
Balance, end of period	$	114,038	$	102,879
* Reconciliation to Revenue Reported per Condensed Consolidated Statement of Operations:	Three Months Ended
	March 31,
(in thousands)	2020		2019
Revenue billed as of the end of period	$	49,609	$	48,281
Increase (decrease) in total unbilled accounts receivable		89		(199)
Revenue Reported in Condensed Consolidated Statement of Operations	$	49,698	$	48,082