Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

The changes in the net carrying amount of goodwill for the years ended December 31, 2017 and 2016, respectively, are as follows (in millions):



Balance as of January 1, 2016	$	7,068
Goodwill related to current year acquisitions	642
Goodwill related to disposals	(34		)
Goodwill related to prior year acquisitions	4
Foreign currency translation	(270		)
Balance as of December 31, 2016	$	7,410
Goodwill related to current year acquisitions	619
Goodwill related to disposals	(5		)
Goodwill related to prior year acquisitions	(13		)
Foreign currency translation	347
Balance as of December 31, 2017	$	8,358

Amortization basis and estimated useful lives by intangible asset type are generally as follows:



Intangible Asset Description	Amortization Basis	Expected Life
Customer related and contract based	In line with underlying cash flows	7 to 20 years
Tradenames	Straight-line	1 to 3 years
Technology	Straight-line	5 to 7 years

Other intangible assets by asset class are as follows (in millions):



	As of December 31
	2017						2016
	Gross Carrying Amount		Accumulated Amortization and Impairment		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization and Impairment		Net Carrying Amount
Customer related and contract based	2,550		1,415		1,135		2,023		1,198		825
Tradenames ⁽¹⁾	1,047		533		514		1,027		7		1,020
Technology and other ⁽¹⁾	416		332		84		347		302		45
Total	$	4,013	$	2,280	$	1,733	$	3,397	$	1,507	$	1,890


(1)	Prior to May 1, 2017, finite lived tradenames were classified within Technology and other. As of December 31, 2016, $29 million of gross carrying amount and $7 million of accumulated amortization related to finite-lived tradenames were reclassified from Technology and other to Tradenames.

The estimated future amortization for finite-lived intangible assets as of December 31, 2017 is as follows (in millions):