Google Inc. | 2013 | FY | 3


Goodwill and Other Intangible Assets
The changes in the carrying amount of goodwill for the year ended December 31, 2013 were as follows (in millions):
 
Balance as of December 31, 2012
$
10,537

Goodwill acquired
1,079

Goodwill disposed
(64
)
Goodwill adjustment
(60
)
Balance as of December 31, 2013
$
11,492


As of December 31, 2013, the amount of goodwill related to the Motorola Mobile segment was not material.
Information regarding our acquisition-related intangible assets is as follows (in millions):
 
 
As of December 31, 2012
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Net
Carrying
Amount
Patents and developed technology
$
7,310

 
$
1,323

 
$
5,987

Customer relationships
2,061

 
847

 
1,214

Trade names and other
576

 
304

 
272

Total
$
9,947

 
$
2,474

 
$
7,473

 
As of December 31, 2013
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Net
Carrying
Value
Patents and developed technology
$
7,282

 
$
2,102

 
$
5,180

Customer relationships
1,770

 
1,067

 
703

Trade names and other
534

 
351

 
183

Total
$
9,586

 
$
3,520

 
$
6,066


Patents and developed technology, customer relationships, and trade names and other have weighted-average useful lives from the date of purchase of 8.1 years, 6.5 years, and 5.3 years. Amortization expense of acquisition-related intangible assets for the years ended December 31, 2011, 2012, and 2013 was $441 million, $884 million, and $1,158 million.
As of December 31, 2013, expected amortization expense for acquisition-related intangible assets for each of the next five years and thereafter was as follows (in millions):
 
2014
$
1,093

2015
934

2016
844

2017
781

2018
734

Thereafter
1,680

 
$
6,066


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