Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 956.1	$ 972.8	$ 354.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	274.0	283.8	290.6
Loss on Extinguishment of Debt	0.0	(74.0)	0.0
Amortization of restricted stock and other non-cash compensation	50.0	70.1	67.0
Net losses on sales of businesses	11.3	19.4	67.0
Non-cash restructuring charges	101.8	9.8	265.6
Net amortization of bond discounts and deferred financing costs	3.0	5.7	11.4
Provision for uncollectible receivables	(8.9)	(14.6)	59.5
Deferred income tax provision	(27.0)	(8.2)	(46.4)
Other	13.4	18.7	20.0
Changes in assets and liabilities, net of acquisitions and divestitures, providing (using) cash:
Accounts receivable	(362.7)	(647.6)	551.4
Accounts receivable, billable to clients	244.5	(571.0)	122.5
Other current assets	(61.1)	(45.9)	11.9
Accounts payable	(408.0)	1,858.1	(27.0)
Accrued liabilities	(102.8)	108.9	179.3
Contract liabilities	17.8	40.9	62.0
Other non-current assets and liabilities	(92.6)	(99.3)	(141.8)
Net cash provided by operating activities	608.8	2,075.6	1,847.2
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	178.1	195.3	167.5
Cash Divested from Deconsolidation	(20.4)	(16.3)	0.0
Acquisitions, net of cash acquired	232.2	0.0	4.9
Proceeds from Hedge, Investing Activities	2.6	34.8	13.5
Other investing activities	(2.0)	(8.5)	(57.3)
Net cash used in investing activities	(430.1)	(185.3)	(216.2)
CASH FLOWS FROM FINANCING ACTIVITIES:
Early Repayment of Senior Debt	0.0	(1,066.8)	0.0
Repayments of long-term debt	0.0	(504.1)	(503.7)
Common stock dividends	(457.3)	(427.7)	(398.1)
Payments for Repurchase of Common Stock	(320.1)	0.0	0.0
Acquisition-related payments	(9.3)	(28.0)	(46.6)
Tax payments for employee shares withheld	(40.3)	(25.5)	(22.3)
Repayments of Senior Debt	29.9	0.0	0.0
Distributions to noncontrolling interests	(12.3)	(15.5)	(19.5)
Net (decrease) increase in short-term borrowings	(29.4)	(10.8)	1.5
Proceeds from Long-term Debt	0.0	998.1	646.2
Exercise of stock options	0.0	8.0	6.5
Other financing activities	(0.8)	(11.9)	(10.2)
Net cash used in financing activities	(899.4)	(1,084.2)	(346.2)
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	1.6	(45.4)	31.0
Net (decrease) increase in cash, cash equivalents and restricted cash	(719.1)	760.7	1,315.8
Cash, cash equivalents and restricted cash at beginning of period	3,272.2	2,511.5	1,195.7
Cash, cash equivalents and restricted cash at end of period	$ 2,553.1	$ 3,272.2	$ 2,511.5