Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 715.7	$ 1,118.1	$ 956.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	258.9	264.3	274.0
Goodwill, Impairment Loss	232.1	0.0	0.0
Amortization of restricted stock and other non-cash compensation	64.8	46.7	50.0
Net losses (gains) on sales of businesses	64.2	(17.9)	11.3
Provision for uncollectible receivables	1.9	7.2	(8.9)
Net amortization of bond discounts and deferred financing costs	1.0	2.0	3.0
Non-cash restructuring charges	(5.0)	(0.9)	101.8
Deferred income tax provision	(28.1)	5.1	(27.0)
Other	46.2	26.8	13.4
Changes in assets and liabilities, net of acquisitions and divestitures, providing (using) cash:
Accounts receivable	(121.2)	(385.3)	(362.7)
Accounts receivable, billable to clients	42.2	(181.4)	244.5
Increase (Decrease) in Prepaid Expense	159.4	46.0	55.6
Increase (Decrease) in Other Current Assets	(44.2)	42.2	5.5
Accounts payable	204.1	47.8	(408.0)
Accrued liabilities	(14.7)	(63.6)	(102.8)
Contract liabilities	(160.7)	(5.4)	17.8
Other non-current assets and liabilities	(131.0)	(220.6)	(59.3)
Net cash provided by operating activities	1,055.2	554.7	642.1
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	141.8	179.3	178.1
Payments to Acquire Investments	25.2	4.2	13.2
Payments to Acquire Marketable Securities	1.2	97.6	0.2
Payments to Acquire Businesses, Net of Cash Acquired, including adjustments for prior period acquisitons	0.0	6.3	232.2
Cash Divested from Deconsolidation	0.0	0.0	(20.4)
Proceeds from Maturities, Prepayments and Calls of Short-Term Investments	2.5	100.7	0.0
Proceeds from Hedge, Investing Activities	3.1	35.1	2.6
Proceeds from Divestiture of Businesses, Net of Cash Divested	7.9	58.7	(22.4)
Other investing activities	3.6	7.5	33.8
Net cash used in investing activities	(151.1)	(85.4)	(430.1)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common stock dividends	(496.5)	(479.1)	(457.3)
Repayments of long-term debt	(250.1)	(0.5)	(0.7)
Payments for Repurchase of Common Stock	230.1	(350.2)	320.1
Distributions to noncontrolling interests	(18.9)	(17.7)	(12.3)
Tax payments for employee shares withheld	(14.1)	(58.9)	(40.3)
Acquisition-related payments	(9.0)	(12.9)	(9.3)
Repayments of Senior Debt	0.0	0.0	29.9
Net increase (decrease) in short-term borrowings	0.2	(8.2)	(29.4)
Proceeds from Long-term Debt	0.2	296.3	0.0
Other financing activities	(1.6)	(3.1)	(0.1)
Net cash used in financing activities	(1,019.9)	(634.3)	(899.4)
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	(82.9)	7.0	(31.7)
Net decrease in cash, cash equivalents and restricted cash	(198.7)	(158.0)	(719.1)
Cash, cash equivalents and restricted cash at beginning of period	2,395.1	2,553.1	3,272.2
Cash, cash equivalents and restricted cash at end of period	$ 2,196.4	$ 2,395.1	$ 2,553.1