Legal and Regulatory Proceedings - Additional Information (Detail) (USD $)	12 Months Ended		12 Months Ended				9 Months Ended
	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2010 Visa Litigation [Member]	Sep. 30, 2011 Visa Litigation [Member]	Sep. 30, 2010 Visa Litigation [Member]	Dec. 31, 2009 Visa Litigation [Member]	Sep. 30, 2011 Upper Limit Trust Preferred Securities [Member]	Jun. 30, 2011 Trust Preferred Securities [Member]	Sep. 30, 2011 Upper Limit
Commitments and Contingencies Disclosure [Line Items]
Remaining litigation reserve						$ 243,000,000
Visa Indemnification Charges			199,000,000
Reserves for litigation		3,000,000	30,000,000	31,000,000	30,000,000
Number of putative securities class action complaints	5
Number of cases that have been consolidated	5
Number of additional lawsuit filed	2
Number of alleging violations of ERISA that were dismissed	2
Debt Instruments Redemption Price								$ 25.18
Total amount of compensation payments							1,000,000
amount in excess of amounts reserved									$ 82,000,000