Changes in Level 3 Liabilities (Detail) (Other Liabilities Member, USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Other Liabilities Member
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Liabilities Beginning Balance	$ 55.2	[1]	$ 81.0	[1]	$ 58.6	[1]	$ 94.4	[1]
Total Realized and Unrealized (Gains) Losses
Included in Earnings	1.4	[1]	(1.7)	[1]	2.7	[1]	(2.4)	[1]
Included in Other Comprehensive Income		[1]		[1]		[1]		[1]
Purchases, Issuances, Sales, and Settlements
Issuances	45.7	[1]	1.8	[1]	53.2	[1]	3.1	[1]
Settlements	(0.1)	[1]	(0.1)	[1]	(12.3)	[1]	(14.1)	[1]
Fair Value Liabilities Ending Balance	102.2	[1]	81.0	[1]	102.2	[1]	81.0	[1]
Unrealized (Gains) Losses Included in Earnings Related to Financial Instruments Held at Period End						[1]		[1]

[1] Balances relate to standby letters of credit, contingent consideration liabilities, and the net estimated liability for Visa related indemnifications.