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	$ 699.7		$ 578.0		$ 513.4
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	93.5		79.2		66.3
Stock-based compensation expense	64.5		56.7		56.6
Goodwill impairment charge	12.2
Deferred income taxes	36.1		10.3		(10.6)
Excess tax benefits from settlement of stock-based compensation awards	(15.7)		(7.4)		(7.0)
Legacy Tax Matters	(12.8)	[1]	(6.4)	[1]
Changes in assets and liabilities:
Accounts receivable	(128.2)		17.1		(54.4)
Other current assets	(14.1)		53.5		(73.5)
Other assets	5.1		7.5		3.7
Accounts payable and accrued liabilities	101.8		24.4		83.5
Restructuring liability	(0.1)		(0.5)		(5.2)
Deferred revenue	20.9		8.8		19.6
Unrecognized tax benefits and other non-current tax liabilities	(49.2)		3.9		30.8
Deferred rent	0.8		7.4		12.0
Other liabilities	8.6		(29.2)		18.1
Net cash provided by operating activities	823.1		803.3		653.3
Cash flows from investing activities
Capital additions	(45.0)		(67.7)		(79.0)
Purchases of short-term investments	(56.2)		(43.3)		(26.2)
Sales and maturities of short-term investments	54.5		40.9		25.0
Cash paid for acquisitions and investment in affiliates, net of cash acquired	(3.5)		(197.5)		(148.6)
Net cash used in investing activities	(50.2)		(267.6)		(228.8)
Cash flows from financing activities
Borrowings under revolving credit facilities					250.0
Repayments of borrowings under revolving credit facilities					(250.0)
Issuance of commercial paper					2,232.8
Repayment of commercial paper					(2,676.4)
Issuance of notes	496.1				496.9
Repayment of notes	(71.3)		(11.3)		(3.8)
Net proceeds from stock plans	116.7		46.4		34.7
Excess tax benefits from settlement of stock-based compensation awards	15.7		7.4		7.0
Cost of treasury shares repurchased	(196.5)		(333.8)		(223.6)
Payment of dividends	(143.0)		(121.0)		(98.6)
Payment of dividends to noncontrolling interests	(8.3)		(5.1)		(4.8)
Payments under capital lease obligations					(1.2)
Contingent consideration paid	(0.5)		(0.3)
Debt issuance costs and related fees	(6.3)				(4.3)
Net cash provided by (used in) financing activities	202.6		(417.7)		(241.3)
Effect of exchange rate changes on cash and cash equivalents	19.9		(17.6)		2.5
Increase in cash and cash equivalents	995.4		100.4		185.7
Cash and cash equivalents, beginning of period	760.0		659.6		473.9
Cash and cash equivalents, end of period	$ 1,755.4		$ 760.0		$ 659.6

[1] The 2012 amount represents a reversal of a liability relating to the favorable resolution of a Legacy tax Matter for the 2005 and 2006 tax years. The 2011 amounts represent a reversal of a liability relating to the lapse of the statute of limitations for a 2004 Legacy Tax Matter.