Unearned Revenue (Tables)

9 Months Ended

Sep. 30, 2019

Unearned Revenue

Schedule of changes in unearned revenue

	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