Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

The following schedule disaggregates various components of the Company's revenue:

	For the Years Ended December 31,
	2020		2019		2018
Marsh:
EMEA	$	2,575	$	2,482	$	2,132
Asia Pacific	1,059		953		683
Latin America	424		460		400
Total International	4,058		3,895		3,215
U.S./Canada	4,537		4,119		3,662
Total Marsh	8,595		8,014		6,877
Guy Carpenter	1,696		1,480		1,286
Subtotal	10,291		9,494		8,163
Fiduciary interest income	46		105		65
Total Risk and Insurance Services	$	10,337	$	9,599	$	8,228
Mercer:
Wealth	$	2,348	$	2,369	$	2,185
Health	1,793		1,796		1,735
Career	787		856		812
Total Mercer	4,928		5,021		4,732
Oliver Wyman Group	2,048		2,122		2,047
Total Consulting	$	6,976	$	7,143	$	6,779

Contract assets and liabilities

The following schedule provides contract assets and contract liabilities information from contracts with customers.

(In millions)	December 31, 2020		December 31, 2019		December 31, 2018
Contract assets	$	236	$	207	$	112
Contract liabilities	$	676	$	593	$	545