Goodwill and Other Intangibles (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in the carrying amount of goodwill

Changes in the carrying amount of goodwill are as follows: 

(In millions of dollars)	2019			2018
Balance as of January 1, as reported	$	9,599		$	9,089
Goodwill acquired (a)	5,124			626
Other adjustments (b)	(52		)	(116		)
Balance at December 31,	$	14,671		$	9,599

(a) Includes $4.9 billion from the acquisition of JLT in 2019.

(b) Primarily reflects the impact of dispositions in 2019 and foreign exchange translation in 2018.

Schedule of finite-lived intangible assets

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

(In millions of dollars)	2019						2018
	Gross Cost		Accumulated Amortization		Net Carrying Amount		Gross Cost		Accumulated Amortization		Net Carrying Amount
Customer relationships	$	3,494	$	897	$	2,597	$	1,970	$	639	$	1,331
Other (a)	380		203		177		259		153		106
Amortized intangibles	$	3,874	$	1,100	$	2,774	$	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 of dollars)
2020	$	344
2021	328
2022	299
2023	278
2024	267
Subsequent years	1,258
	$	2,774