DEFERRED REVENUE AND PERFORMANCE OBLIGATIONS

12 Months Ended

Dec. 31, 2019

Revenue from Contract with Customer [Abstract]

DEFERRED REVENUE AND PERFORMANCE OBLIGATIONS

DISAGGREGATION OF REVENUE

The tables below show disaggregation of revenue into categories that reflect how economic factors affect the nature, amount, timing, and uncertainty of revenue and cash flows.

Timing of Revenue Recognition

Timing of revenue recognition by revenue category during the period is as follows:

For the year ended December 31, 2019	Products and services transferred at a point in time		Products and services transferred over time		Total
Revenues:
Software licenses and royalties	$	84,900	$	15,305	$	100,205
Subscriptions	—		296,352		296,352
Software services	—		213,061		213,061
Maintenance	—		430,318		430,318
Appraisal services	—		23,479		23,479
Hardware and other	23,012		—		23,012
Total	$	107,912	$	978,515	$	1,086,427

For the year ended December 31, 2018	Products and services transferred at a point in time		Products and services transferred over time		Total
Revenues:
Software licenses and royalties	$	75,188	$	18,253	$	93,441
Subscriptions	—		220,547		220,547
Software services	—		191,269		191,269
Maintenance	—		384,521		384,521
Appraisal services	—		21,846		21,846
Hardware and other	23,658		—		23,658
Total	$	98,846	$	836,436	$	935,282

For the year ended December 31, 2017	Products and services transferred at a point in time		Products and services transferred over time		Total
Revenues:
Software licenses and royalties	$	69,167	$	17,075	$	86,242
Subscriptions	—		172,176		172,176
Software services	—		180,460		180,460
Maintenance	—		359,319		359,319
Appraisal services	—		25,023		25,023
Hardware and other	17,679		—		17,679
Total	$	86,846	$	754,053	$	840,899

Recurring Revenue

The majority of our revenue is comprised of recurring revenues from maintenance and subscriptions. Virtually all of our on-premises software clients contract with us for maintenance and support, which provides us with a significant source of recurring revenue. We generally provide maintenance and support for our on-premises clients under annual, or in some cases, multi-year contracts. The contract terms for subscription arrangements range from one to 10 years but are typically contracted for initial periods of three to five years. Non-recurring revenues are derived from all other revenue categories.

Recurring revenues and non-recurring revenues recognized during the period are as follows:

For the year ended December 31, 2019	Enterprise Software		Appraisal and Tax		Corporate			Totals
Recurring revenues	$	690,156	$	36,514	$	—		$	726,670
Non-recurring revenues	295,193		58,308		6,256			359,757
Intercompany	15,496		—		(15,496		)	—
Total revenues	$	1,000,845	$	94,822	$	(9,240	)	$	1,086,427

For the year ended December 31, 2018	Enterprise Software		Appraisal and Tax		Corporate			Totals
Recurring revenues	$	570,645	$	34,424	$	—		$	605,069
Non-recurring revenues	269,400		55,932		4,881			330,213
Intercompany	13,155		—		(13,155		)	—
Total revenues	$	853,200	$	90,356	$	(8,274	)	$	935,282

For the year ended December 31, 2017	Enterprise Software		Appraisal and Tax		Corporate			Totals
Recurring revenues	$	502,018	$	29,477	$	—		$	531,495
Non-recurring revenues	252,690		52,102		4,612			309,404
Intercompany	10,425		—		(10,425		)	—
Total revenues	$	765,133	$	81,579	$	(5,813	)	$	840,899

DEFERRED REVENUE AND PERFORMANCE OBLIGATIONS

Total deferred revenue, including long-term, by segment is as follows:

	December 31, 2019		December 31, 2018
Enterprise Software	$	386,115	$	327,521
Appraisal and Tax	25,210		20,018
Corporate	1,369		3,397
Totals	$	412,694	$	350,936

Changes in total deferred revenue, including long-term, were as follows:

	2019
Balance at beginning of year	$	350,936
Deferral of revenue	993,109
Recognition of deferred revenue	(931,351		)
Balance at end of year	$	412,694

Transaction Price Allocated to the Remaining Performance Obligations

The aggregate amount of transaction price allocated to the remaining performance obligations represents contracted revenue that has not yet been recognized ("Backlog"), which includes deferred revenue and amounts that will be invoiced and recognized as revenue in future periods. Backlog as of December 31, 2019 was $1.46 billion, of which we expect to recognize approximately 49% as revenue over the next 12 months and the remainder thereafter.

DEFERRED COMMISSIONS

Sales commissions earned by our sales force are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions for initial contracts are deferred and then amortized commensurate with the recognition of associated revenue over a period of benefit that we have determined to be three to seven years. Deferred commissions were $29.8 million, $21.9 million, as of December 31, 2019, and 2018 respectively. Amortization expense was $17.8 million $15.6 million, $11.2 million for the twelve months ended December 31, 2019, 2018, and 2017, respectively. There were no indicators of impairment in relation to the costs capitalized for the periods presented. Deferred commissions have been included with prepaid expenses in the accompanying consolidated balance sheets. Amortization expense related to deferred commissions is included in selling, general and administrative expenses in the accompanying consolidated statements of comprehensive income.