Goodwill and Other Intangibles (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in the Carrying Amount of Goodwill

Changes in the carrying amount of goodwill are as follows:

March 31,
(In millions)	2018		2017
Balance as of January 1,	$	9,089	$	8,369
Goodwill acquired	15		363
Other adjustments(a)	90		37
Balance at March 31,	$	9,194	$	8,769

Amortized Intangible Assets

The gross cost and accumulated amortization at March 31, 2018 and December 31, 2017 are as follows:

	March 31, 2018						December 31, 2017
(In millions)	Gross Cost		Accumulated Amortization		Net Carrying Amount		Gross Cost		Accumulated Amortization		Net Carrying Amount
Client Relationships	$	1,700	$	560	$	1,140	$	1,672	$	518	$	1,154
Other (a)	241		125		116		234		114		120
Amortized intangibles	$	1,941	$	685	$	1,256	$	1,906	$	632	$	1,274

^(a) Primarily non-compete agreements, trade names and developed technology.

Estimated Future Aggregate Amortization Expense

The estimated future aggregate amortization expense is as follows:

For the Years Ending December 31,
(In millions)	Estimated Expense
2018 (excludes amortization through March 31, 2018)	$	137
2019	174
2020	154
2021	145
2022	132
Subsequent years	514
	$	1,256