Goodwill and Other Intangibles (Tables)

6 Months Ended

Jun. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in the Carrying Amount of Goodwill

Changes in the carrying amount of goodwill are as follows:

June 30,
(In millions)	2019			2018
Balance as of January 1,	$	9,599		$	9,089
Goodwill acquired (a)	4,895			116
Other adjustments(b)	(15		)	(28		)
Balance at June 30,	$	14,479		$	9,177

^(a) Primarily reflects the acquisition of JLT in 2019 of $4.7 billion.

^(b) Primarily reflects the impact of foreign exchange.

Amortized Intangible Assets

The gross cost and accumulated amortization of identified intangible assets at June 30, 2019 and December 31, 2018 are as follows:

	June 30, 2019						December 31, 2018
(In millions)	Gross Cost		Accumulated Amortization		Net Carrying Amount		Gross Cost		Accumulated Amortization		Net Carrying Amount
Client Relationships	$	3,664	$	765	$	2,899	$	1,970	$	639	$	1,331
Other (a)	365		181		184		259		153		106
Amortized intangibles	$	4,029	$	946	$	3,083	$	2,229	$	792	$	1,437

^(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
2019 (excludes amortization through June 30, 2019)	$	194
2020	371
2021	359
2022	345
2023	336
Subsequent years	1,478
	$	3,083