Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME		$ 1,064	$ 1,024	$ 4,236
Adjustments to reconcile net income to total net cash from operating activities:
Depreciation		242	255	281
Amortization		263	312	369
Impairment		0	81	0
Non-cash restructuring charges		38	71	0
Non-cash lease expense		105	120	160
Net periodic benefit of defined benefit pension plans		(26)	(153)	(168)
Provision for doubtful receivables from clients		6	13	19
(Benefit from)/provision for deferred income taxes		(109)	(50)	226
Share-based compensation		125	99	101
Net (gain)/loss on disposal of operations		(43)	59	(2,679)
Non-cash foreign exchange loss/(gain)		20	(137)	(10)
Other, net		31	6	(25)
Changes in operating assets and liabilities, net of effects from purchase of subsidiaries:
Accounts receivable		(206)	(188)	(134)
Other assets		(185)	(197)	(122)
Other liabilities		16	(495)	(175)
Provisions		4	(8)	(18)
Net cash from operating activities		1,345	812	2,061
CASH FLOWS (USED IN)/FROM INVESTING ACTIVITIES
Additions to fixed assets and software for internal use		(153)	(138)	(148)
Capitalized software costs		(89)	(66)	(53)
Acquisitions of operations, net of cash acquired		(6)	(81)	(47)
Net proceeds/(payments) from sale of operations		89	(59)	4,048
Cash and fiduciary funds transferred in sale of operations		(922)	(29)	(1,030)
(Purchase)/sale of investments		(4)	200	(200)
Net cash (used in)/from investing activities		(1,085)	(173)	2,570
CASH FLOWS USED IN FINANCING ACTIVITIES
Senior notes issued		748	750	0
Debt issuance costs		(7)	(5)	(4)
Repayments of debt		(254)	(585)	(1,008)
Repurchase of shares		(1,000)	(3,530)	(1,627)
Proceeds from issuance of shares		0	7	10
Net (payments)/proceeds from fiduciary funds held for clients		(234)	354	(40)
Payments of deferred and contingent consideration related to acquisitions		(12)	(22)	(19)
Cash paid for employee taxes on withholding shares		(26)	(34)	(16)
Dividends paid		(352)	(369)	(374)
Acquisitions of and dividends paid to non-controlling interests		(63)	(11)	(36)
Net cash used in financing activities		(1,200)	(3,445)	(3,114)
(DECREASE)/INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	[1]	(940)	(2,806)	1,517
Effect of exchange rate changes on cash, cash equivalents and restricted cash		11	(164)	(127)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF YEAR	[1]	4,721	7,691	6,301
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF YEAR	[1]	$ 3,792	$ 4,721	$ 7,691

[1] The amounts of cash, cash equivalents and restricted cash, their respective classification on the consolidated balance sheets as well as their respective portions of the increase or decrease in cash, cash equivalents and restricted cash for each of the periods presented have been included in Note 21 — Supplemental Disclosures of Cash Flow Information.