Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Revenue	$ 2,244	$ 2,160
Costs of providing services
Salaries and benefits	1,313	1,318
Other operating expenses	453	486
Depreciation	60	66
Amortization	71	85
Restructuring costs	3	6
Transaction and transformation	59	20
Total costs of providing services	1,959	1,981
Income from operations	285	179
Interest expense	(54)	(49)
Other income, net	25	27
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	256	157
Provision for income taxes	(50)	(43)
INCOME FROM CONTINUING OPERATIONS	206	114
Income from discontinued operations, net of tax	0	11
NET INCOME	206	125
Income attributable to non-controlling interests	(3)	(3)
NET INCOME ATTRIBUTABLE TO WTW	$ 203	$ 122
Basic earnings per share:
Income from continuing operations per share	$ 1.89	$ 0.94
Income from discontinued operations per share	0	0.09
Basic earnings per share	1.89	1.03
Diluted earnings per share:
Income from continuing operations per share	1.88	0.94
Income from discontinued operations per share	0	0.09
Diluted earnings per share	$ 1.88	$ 1.03
Comprehensive income before non-controlling interests	$ 259	$ 69
Comprehensive income attributable to non-controlling interests	(3)	(3)
Comprehensive income attributable to WTW	$ 256	$ 66