Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 972.8	$ 354.2	$ 673.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	283.8	290.6	278.5
Loss on Extinguishment of Debt	74.0	0.0	0.0
Amortization of restricted stock and other non-cash compensation	70.1	67.0	80.2
Net losses on sales of businesses	19.4	67.0	43.4
Non-cash restructuring charges	9.8	265.6	11.7
Net amortization of bond discounts and deferred financing costs	5.7	11.4	9.3
Provision for uncollectible receivables	(14.6)	59.5	10.1
Deferred income tax provision	(8.2)	(46.4)	9.7
Other	18.7	20.0	6.8
Changes in assets and liabilities, net of acquisitions and divestitures, providing (using) cash:
Accounts receivable	(647.6)	551.4	(111.2)
Accounts receivable, billable to clients	(571.0)	122.5	(38.7)
Other current assets	(45.9)	11.9	(27.2)
Accounts payable	1,858.1	(27.0)	546.0
Accrued liabilities	108.9	179.3	27.4
Contract liabilities	40.9	62.0	46.5
Other non-current assets and liabilities	(99.3)	(141.8)	(37.2)
Net cash provided by operating activities	2,075.6	1,847.2	1,529.2
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	195.3	167.5	198.5
Cash Divested from Deconsolidation	(16.3)	0.0	0.0
Acquisitions, net of cash acquired	0.0	4.9	0.6
Proceeds from Hedge, Investing Activities	34.8	13.5	3.8
Other investing activities	(8.5)	(57.3)	33.6
Net cash used in investing activities	(185.3)	(216.2)	(161.7)
CASH FLOWS FROM FINANCING ACTIVITIES:
Early Repayment of Senior Debt	(1,066.8)	0.0	0.0
Repayments of long-term debt	(504.1)	(503.7)	(403.3)
Common stock dividends	(427.7)	(398.1)	(363.1)
Acquisition-related payments	(28.0)	(46.6)	(15.8)
Tax payments for employee shares withheld	(25.5)	(22.3)	(22.4)
Distributions to noncontrolling interests	(15.5)	(19.5)	(21.6)
Net (decrease) increase in short-term borrowings	(10.8)	1.5	(19.8)
Proceeds from Long-term Debt	998.1	646.2	0.0
Exercise of stock options	8.0	6.5	4.3
Other financing activities	(11.9)	(10.2)	(1.3)
Net cash used in financing activities	(1,084.2)	(346.2)	(843.0)
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	(45.4)	31.0	(6.0)
Net increase in cash, cash equivalents and restricted cash	760.7	1,315.8	518.5
Cash, cash equivalents and restricted cash at beginning of period	2,511.5	1,195.7	677.2
Cash, cash equivalents and restricted cash at end of period	$ 3,272.2	$ 2,511.5	$ 1,195.7