Intangible Assets

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Intangible Assets

Intangible assets consisted of the following:

(In millions)	Gross Carrying Amount		Accumulated Amortization		Net Book Value
September 30, 2018
Customer related intangible assets	$	2,292	$	1,260	$	1,032
Acquired software and technology	578		483		95
Trade names	117		69		48
Capitalized software development costs	783		301		482
Purchased software	262		117		145
Total	$	4,032	$	2,230	$	1,802

(In millions)	Gross Carrying Amount		Accumulated Amortization		Net Book Value
December 31, 2017
Customer related intangible assets	$	2,293	$	1,168	$	1,125
Acquired software and technology	579		460		119
Trade names	117		64		53
Capitalized software development costs	737		282		455
Purchased software	241		111		130
Total	$	3,967	$	2,085	$	1,882

The Company estimates that annual amortization expense with respect to acquired intangible assets recorded at September 30, 2018, which include customer related intangible assets, acquired software and technology, and trade names, will be approximately $160 million in each of 2018 and 2019, $130 million in each of 2020 and 2021, and $120 million in 2022. Amortization expense with respect to capitalized and purchased software recorded at September 30, 2018 is estimated to approximate $180 million in 2018.