Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,263.0	$ 1,430.0	$ 1,422.0
Income from discontinued operations, net of tax	828.0	177.0	169.0
Adjustments to reconcile net income to cash provided by operating activities:
Loss (gain) from sales of businesses and investments, net	16.0	(39.0)	(81.0)
Depreciation of fixed assets	187.0	162.0	164.0
Amortization and impairment of intangible assets	704.0	157.0	174.0
Share-based compensation expense	319.0	306.0	320.0
Deferred income taxes	(18.0)	(24.0)	(223.0)
Change in assets and liabilities:
Fiduciary receivables	171.0	595.0	599.0
Short-term investments — funds held on behalf of clients	(135.0)	(540.0)	206.0
Fiduciary liabilities	(36.0)	(55.0)	(805.0)
Receivables, net	(254.0)	(105.0)	(97.0)
Accounts payable and accrued liabilities	96.0	53.0	88.0
Restructuring reserves	172.0	0.0	0.0
Current income taxes	(914.0)	(42.0)	24.0
Pension, other postretirement and other postemployment liabilities	(66.0)	42.0	(230.0)
Other assets and liabilities	(8.0)	66.0	110.0
Cash provided by operating activities - continuing operations	669.0	1,829.0	1,502.0
Cash provided by operating activities - discontinued operations	65.0	497.0	507.0
CASH PROVIDED BY OPERATING ACTIVITIES	734.0	2,326.0	2,009.0
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from investments	68.0	43.0	220.0
Payments for investments	(64.0)	(64.0)	(266.0)
Net sales (purchases) of short-term investments — non-fiduciary	(232.0)	61.0	9.0
Acquisition of businesses, net of cash acquired	(1,029.0)	(879.0)	(16.0)
Sale of businesses, net of cash sold	4,246.0	107.0	205.0
Capital expenditures	(183.0)	(156.0)	(200.0)
Cash provided by (used for) investing activities - continuing operations	2,806.0	(888.0)	(48.0)
Cash provided by (used for) investing activities - discontinued operations	(19.0)	(66.0)	(90.0)
CASH PROVIDED BY (USED FOR) INVESTING ACTIVITIES	2,787.0	(954.0)	(138.0)
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	(2,399.0)	(1,257.0)	(1,550.0)
Issuance of shares for employee benefit plans	(121.0)	(129.0)	(30.0)
Issuance of debt	1,654.0	3,467.0	5,351.0
Repayment of debt	(1,999.0)	(2,945.0)	(5,098.0)
Cash dividends to shareholders	(364.0)	(345.0)	(323.0)
Noncontrolling interests and other financing activities	(36.0)	(77.0)	(39.0)
Cash used for financing activities - continuing operations	(3,265.0)	(1,286.0)	(1,689.0)
Cash used for financing activities - discontinued operations	0.0	0.0	0.0
CASH USED FOR FINANCING ACTIVITIES	(3,265.0)	(1,286.0)	(1,689.0)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	69.0	(39.0)	(172.0)
NET INCREASE IN CASH AND CASH EQUIVALENTS	325.0	47.0	10.0
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	431.0	384.0	374.0
CASH AND CASH EQUIVALENTS AT END OF YEAR	756.0	431.0	384.0
Supplemental disclosures:
Interest paid	272.0	272.0	254.0
Income taxes paid, net of refunds	$ 1,182.0	$ 218.0	$ 249.0