v3.5.0.2
Deferred Revenue Deferred Revenue
 6 Months Ended
Jun. 30, 2016
Revenue Recognition [Abstract]  
Deferred Revenue Disclosure [Text Block]
Deferred Revenue

Deferred revenue represents cash received that is yet to be recognized as revenue. Total deferred revenue was $442 million as of June 30, 2016, including $330 million in current deferred revenue and $112 million in non-current deferred revenue. The changes in our deferred revenue during the six months ended June 30, 2016 are as follows (in millions):
 
Annual Listings Revenue
 
Original Listings Revenues
 
Other Listings Revenues
 
Data Services and Other Revenues
 
Total
Deferred revenue balance at December 31, 2015
$
—

 
$
50

 
$
59

 
$
81

 
$
190

Additions
363

 
12

 
43

 
263

 
681

Amortization
(183
)
 
(4
)
 
(21
)
 
(221
)
 
(429
)
Deferred revenue balance at June 30, 2016
$
180

 
$
58

 
$
81

 
$
123

 
$
442