Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,020	$ 1,010	$ 732
Adjustments to reconcile net income to cash provided by operating activities:
(Gain) loss from sales of businesses, net		(6)	43
Depreciation of fixed assets	232	220	151
Amortization of intangible assets	423	362	154
Share-based compensation expense	212	235	221
Deferred income taxes	(95)	146	76
Change in assets and liabilities:
Fiduciary receivables	(1,402)	(14)	816
Short-term investments - funds held on behalf of clients	239	(713)	(19)
Fiduciary liabilities	1,163	727	(797)
Receivables, net	106	(494)	(69)
Accounts payable and accrued liabilities	(37)		(280)
Restructuring reserves	(46)	(73)	(64)
Current income taxes	185	120
Pension and other post employment liabilities	(585)	(399)	(130)
Other assets and liabilities	4	(103)	(51)
CASH PROVIDED BY OPERATING ACTIVITIES	1,419	1,018	783
CASH FLOWS FROM INVESTING ACTIVITIES
Sale of long-term investments	178	190	90
Purchase of long-term investments	(12)	(30)	(34)
Net sale (purchase) of short-term investments - non-fiduciary	440	(8)	(337)
Acquisition of businesses, net of cash acquired	(160)	(97)	(2,078)
Capital expenditures	(269)	(241)	(180)
CASH PROVIDED BY (USED FOR) INVESTING ACTIVITIES	177	(186)	(2,539)
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	(1,125)	(828)	(250)
Issuance of shares for employee benefit plans	118	201	194
Issuance of debt	733	1,673	2,905
Repayment of debt	(1,077)	(1,688)	(816)
Cash dividends to shareholders	(204)	(200)	(175)
Purchase of shares from noncontrolling interests	(4)	(24)	(15)
Dividends paid to noncontrolling interests	(27)	(30)	(20)
CASH (USED FOR) PROVIDED BY FINANCING ACTIVITIES	(1,586)	(896)	1,823
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	9	(10)	62
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	19	(74)	129
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	272	346	217
CASH AND CASH EQUIVALENTS AT END OF YEAR	291	272	346
Supplemental disclosures:
Interest paid	232	240	158
Income taxes paid, net of refunds	238	77	192
Non-cash transactions:
Acquisition of Hewitt, common stock issued and stock options assumed			$ 2,474