Deferred Revenue

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Deferred Revenue

Deferred Revenue

Deferred revenue as of December 31, 2020 and 2019 consisted of the following (in thousands):

	As of December 31, 2020		As of December 31, 2019
Product, subscription and support, current	$	503,740	$	508,580
Professional services, current	109,969		95,364
Total deferred revenue, current	$	613,709	$	603,944
Product, subscription and support, non-current	341,541		369,589
Professional services, non-current	1,207		1,034
Total deferred revenue, non-current	$	342,748	$	370,623
Total deferred revenue	$	956,457	$	974,567

Changes in the balance of deferred revenue for the periods presented are as follows (in thousands):

	Deferred Revenue
Balance at December 31, 2018	$	934,828
Billings for the period	926,141
Revenue recognized	(889,152)
Assumed in connection with acquisitions	2,750
Balance at December 31, 2019	$	974,567
Billings for the period	919,810
Revenue recognized	(940,584)
Assumed in connection with acquisitions	2,664
Balance at December 31, 2020	$	956,457

Remaining Performance Obligations

Transaction price allocated to remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue and non-cancelable contracts that will be invoiced and recognized as revenue in future periods ("backlog"). While deferred revenue is recorded on our balance sheet as a liability, backlog is not recorded in revenue, deferred revenue or elsewhere in our consolidated financial statements until we establish a contractual right to invoice, at which point it is recorded as revenue or deferred revenue as appropriate. As of December 31, 2020, the aggregate amount of the transaction price allocated to remaining performance obligations was $956.5 million in deferred revenue and $52.0 million in backlog. As of December 31, 2019, the aggregate amount of the transaction price allocated to remaining performance obligations was $974.6 million in deferred revenue and $15.1 million in backlog.

We expect that the amount of backlog relative to the total value of our contracts will change from year to year due to several factors, including the amount invoiced early in the contract term, the timing and duration of customer agreements, varying invoicing cycles of agreements and changes in customer financial circumstances. Accordingly, we believe that fluctuations in backlog are not always a reliable indicator of future revenues and we do not utilize backlog internally as a key management metric.

We expect to recognize these remaining performance obligations as follows (in percentages):

	Total	Less than 1 year	1-2 years	2-3 years	More than 3 years
Deferred revenue	100%	64%	22%	10%	4%
Backlog	100%	56%	24%	15%	5%