Deferred Revenue (Tables)

6 Months Ended

Jun. 30, 2018

Revenue from Contract with Customer [Abstract]

Schedule of Changes in Deferred Revenue

The changes in our deferred revenue during the six months endedJune 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			13			26			230			652
Amortization	(191		)	(12		)	(17		)	(184		)	(404		)
Deferred revenue balance at June 30, 2018	$	192		$	26		$	107		$	139		$	464

The changes in our deferred revenue during the six months endedJune 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		$	88		$	194
Additions	366			11			39			232			648
Amortization	(184		)	(11		)	(21		)	(186		)	(402		)
Divestitures	—			—			—			(10		)	(10		)
Deferred revenue balance at June 30, 2017	$	182		$	23		$	101		$	124		$	430

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

	Annual Listings Revenues		Original Listing Revenues		Other Listing Revenues		Data Services and Other Revenues		Total
Remainder of 2018	$	192	$	13	$	10	$	115	$	330
2019	—		12		34		20		66
2020	—		1		27		2		30
2021	—		—		19		2		21
2022	—		—		13		—		13
Thereafter	—		—		4		—		4
Total	$	192	$	26	$	107	$	139	$	464