Deferred Revenue (Tables)

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Schedule of Changes in Deferred Revenue

The changes in our deferred revenue during the nine months endedSeptember 30, 2018 are as follows (in millions), adjusted to reflect the adoption of ASC 606 as discussed in Note 2:

	Annual Listings Revenues			Original Listings Revenues			Other Listings Revenues			Data Services and Other Revenues			Total
Deferred revenue balance at December 31, 2017	$	—		$	25		$	98		$	93		$	216
Additions	383			17			36			291			727
Amortization	(288		)	(17		)	(27		)	(272		)	(604		)
Deferred revenue balance at September 30, 2018	$	95		$	25		$	107		$	112		$	339

The changes in our deferred revenue during the nine months endedSeptember 30, 2017 are as follows (in millions), adjusted to reflect the adoption of ASC 606 as discussed in Note 2:

	Annual Listings Revenues			Original Listings Revenues			Other Listings Revenues			Data Services and Other Revenues			Total
Deferred revenue balance at December 31, 2016	$	—		$	23		$	83		$	92		$	198
Additions	367			17			49			307			740
Amortization	(276		)	(15		)	(31		)	(286		)	(608		)
Divestitures	—			—			—			(10		)	(10		)
Deferred revenue balance at September 30, 2017	$	91		$	25		$	101		$	103		$	320

As of September 30, 2018, we estimate that our deferred revenue will be recognized in the following years (in millions):

	Annual Listings Revenues		Original Listings Revenues		Other Listings Revenues		Data Services and Other Revenues		Total
Remainder of 2018	$	95	$	8	$	8	$	68	$	179
2019	—		15		34		39		88
2020	—		2		27		3		32
2021	—		—		19		2		21
2022	—		—		13		—		13
Thereafter	—		—		6		—		6
Total	$	95	$	25	$	107	$	112	$	339