Intangible Assets

9 Months Ended

Sep. 30, 2017

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, 2017
Customer related intangible assets	$	2,253	$	1,136	$	1,117
Acquired software and technology	587		452		135
Trade names	117		62		55
Capitalized software development costs	714		272		442
Purchased software	248		109		139
Total	$	3,919	$	2,031	$	1,888

(In millions)	Gross Carrying Amount		Accumulated Amortization		Net Book Value
December 31, 2016
Customer related intangible assets	$	2,200	$	1,043	$	1,157
Acquired software and technology	507		432		75
Trade names	117		57		60
Capitalized software development costs	641		233		408
Purchased software	230		97		133
Total	$	3,695	$	1,862	$	1,833

The Company estimates that annual amortization expense with respect to acquired intangible assets recorded at September 30, 2017, which include customer related intangible assets, acquired software and technology, and trade names, will be approximately $160 million in each of 2017, 2018, and 2019, $140 million in 2020, and $130 million in 2021. Annual amortization expense in 2017 with respect to capitalized and purchased software is estimated to approximate $150 million.