Aon plc | 2013 | FY | 3

Goodwill and Other Intangible Assets
The changes in the net carrying amount of goodwill by operating segment for the years ended December 31, 2013 and 2012, respectively, are as follows (in millions):
 
Risk
Solutions
 
HR
Solutions
 
Total
Balance as of January 1, 2012
$
5,557

 
$
3,213

 
$
8,770

Goodwill related to acquisitions
49

 
47

 
96

Goodwill related to disposals
(1
)
 
—

 
(1
)
Goodwill related to other prior year acquisitions
(6
)
 
—

 
(6
)
Transfers (1)
313

 
(313
)
 
—

Foreign currency translation
70

 
14

 
84

Balance as of December 31, 2012
$
5,982

 
$
2,961

 
$
8,943

Goodwill related to acquisitions
36

 
2

 
38

Goodwill related to disposals
(9
)
 
(3
)
 
(12
)
Goodwill related to other prior year acquisitions
(2
)
 
17

 
15

Foreign currency translation
13

 
—

 
13

Balance as of December 31, 2013
$
6,020

 
$
2,977

 
$
8,997

(1)
Effective January 1, 2012, the Health and Benefits Consulting business was transferred from the HR Solutions segment to the Risk Solutions segment.
Other intangible assets by asset class are as follows (in millions):
 
As of December 31
 
2013
 
2012
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Net
Carrying
Amount
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Net
Carrying
Amount
Intangible assets with indefinite lives:
 
 
 
 
 
 
 
 
 
 
 
Tradenames
$
1,019

 
$
—

 
$
1,019

 
$
1,025

 
$
—

 
$
1,025

Intangible assets with finite lives:
 
 
 
 
 
 
 
 
 
 
 
Customer related and contract based
2,720

 
1,310

 
1,410

 
2,714

 
969

 
1,745

Marketing, technology and other (1)
584

 
435

 
149

 
619

 
414

 
205

 
$
4,323

 
$
1,745

 
$
2,578

 
$
4,358

 
$
1,383

 
$
2,975

(1)
Tradenames with finite lives disclosed separately in prior years are now presented in Marketing, technology, and other.
Amortization expense from finite-lived intangible assets was $395 million, $423 million and $362 million during 2013, 2012 and 2011, respectively.
The estimated future amortization for intangible assets as of December 31, 2013 is as follows (in millions):
 
Risk
Solutions
 
HR
Solutions
 
Total
2014
$
98

 
$
243

 
$
341

2015
83

 
212

 
295

2016
72

 
177

 
249

2017
59

 
141

 
200

2018
42

 
94

 
136

Thereafter
76

 
262

 
338

 
$
430

 
$
1,129

 
$
1,559

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