Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 2,568.1	$ 3,796.0	$ 3,002.2
Short-term investments, at cost	1.9	0.4
Accounts receivable, net of allowance for doubtful accounts of $29.1 and $32.1	7,198.8	8,083.8
Work in process	1,378.0	1,110.6
Other current assets	1,191.7	1,125.2
Total Current Assets	12,338.5	14,116.0
Property and Equipment at cost, less accumulated depreciation of $1,297.5 and $1,279.2	691.7	690.9
Equity Method Investments	122.4	120.3
Goodwill	9,635.4	9,337.5	8,976.1
Intangible Assets, net of accumulated amortization of $911.4 and $879.9	424.7	368.4
Other Assets	300.4	298.1
TOTAL ASSETS	23,513.1	24,931.2
Current Liabilities:
Accounts payable	10,159.2	11,574.6
Customer advances	1,214.3	1,266.7
Short-term debt	8.6	11.8
Taxes payable	359.7	330.0
Other current liabilities	1,857.0	1,925.8
Total Current Liabilities	13,598.8	15,108.9
Long-Term Debt	4,885.0	4,912.9
Long-Term Liabilities	1,182.8	1,091.2
Deferred Tax Liabilities	454.4	483.6
Commitments and Contingent Liabilities (Note 11)
Temporary Equity - Redeemable Noncontrolling Interests	175.3	182.4
Shareholders’ Equity:
Preferred stock	0.0	0.0
Common stock	44.6	44.6
Additional paid-in capital	833.0	828.3
Retained earnings	6,360.1	6,210.6
Accumulated other comprehensive income (loss)	(875.1)	(963.0)	$ (1,356.0)
Treasury stock, at cost	(3,736.2)	(3,505.4)
Total Shareholders’ Equity	2,626.4	2,615.1
Noncontrolling interests	590.4	537.1
Total Equity	3,216.8	3,152.2
TOTAL LIABILITIES AND EQUITY	$ 23,513.1	$ 24,931.2