Reinsurance Arrangements and Guarantees - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	12 Months Ended			87 Months Ended			3 Months Ended	12 Months Ended						3 Months Ended										3 Months Ended					1 Months Ended	3 Months Ended	12 Months Ended											1 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Mar. 31, 2012	Mar. 31, 2012 Contingent Consideration	Dec. 31, 2011 Contingent Consideration	Mar. 31, 2012 Non Agency Securities [Member]	Dec. 31, 2011 Non Agency Securities [Member]	Dec. 31, 2010 Non Agency Securities [Member]	Dec. 31, 2009 Non Agency Securities [Member]	Mar. 31, 2012 Agency Securities	Dec. 31, 2011 Agency Securities	Mar. 31, 2012 Ginnie Mae	Mar. 31, 2012 Mortgage Reinsurance Contracts	Mar. 31, 2011 Mortgage Reinsurance Contracts	Dec. 31, 2011 Mortgage Reinsurance Contracts	Mar. 31, 2012 Mortgage Reinsurance Contracts Upper Limit	Mar. 31, 2012 Standby Letters of Credit	Dec. 31, 2011 Standby Letters of Credit	Mar. 31, 2012 Mortgage Loans and Mortgage Servicing Rights	Dec. 31, 2011 Mortgage Loans and Mortgage Servicing Rights	Mar. 31, 2012 Mortgage Loans and Mortgage Servicing Rights Sales	Dec. 31, 2011 Mortgage Loans and Mortgage Servicing Rights Sales	Mar. 31, 2012 Mortgage Loans and Mortgage Servicing Rights, Repurchase Reserves	Mar. 31, 2011 Mortgage Loans and Mortgage Servicing Rights, Repurchase Reserves	Dec. 31, 2011 Mortgage Loans and Mortgage Servicing Rights, Repurchase Reserves	Mar. 31, 2012 Mortgage Loans and Mortgage Servicing Rights, Repurchase Reserves Non Performing Loans	Dec. 31, 2011 Mortgage Loans and Mortgage Servicing Rights, Repurchase Reserves Non Performing Loans	May 31, 2009 Visa Interest	Mar. 31, 2012 Visa Interest	Dec. 31, 2011 Visa Interest	Dec. 31, 2010 Visa Interest	Mar. 31, 2012 Tax Credit Sales [Member]	Dec. 31, 2011 Tax Credit Sales [Member]	Mar. 31, 2012 Derivative Financial Instruments, Liabilities [Member]		Dec. 31, 2011 Derivative Financial Instruments, Liabilities [Member]	Mar. 31, 2012 Not Designated as Hedging Instrument [Member] Derivative Financial Instruments, Liabilities [Member]		Dec. 31, 2011 Not Designated as Hedging Instrument [Member] Derivative Financial Instruments, Liabilities [Member]		May 31, 2009 Not Designated as Hedging Instrument [Member] Derivative Financial Instruments, Liabilities [Member] Visa Interest
Mortgage loans were covered by such mortgage reinsurance contracts															$ 7,600,000,000		$ 8,000,000,000
Total loss exposure ceded to the Company															302,000,000		309,000,000
Maximum amount of loss exposure based on funds held in each seperate trust account, including net premiums due to the trust accounts															33,000,000
Maximum Exposure to Loss Reserves															30,000,000		38,000,000
Provision For Losses, Mortgage Reinsurance															6,000,000	7,000,000
Future reported losses																		3,000,000
Future cash losses																		3,000,000
Premium income, mortgage reinsurance															5,000,000	8,000,000
Maximum potential amount obligation																			4,800,000,000	5,200,000,000														37,000,000
Fair value of contingent payments						10,000,000	10,000,000												104,000,000	105,000,000	383,000,000	320,000,000	9,000,000	8,000,000
Guarantee obligations, carrying value						10,000,000	10,000,000												104,000,000	105,000,000	383,000,000	320,000,000	9,000,000	8,000,000
Loans sold from January 1, 2005 to September 30, 2011	250,300,000,000				250,300,000,000			30,300,000,000				192,400,000,000		27,600,000,000
Loans Sold Repurchased Request Amount	448,000,000	1,700,000,000	1,100,000,000	1,100,000,000	5,700,000,000			3,000,000	50,000,000	55,000,000	99,000,000
Unpaid principal balance of loans related to unresolved requests previously received from investors	564,000,000	590,000,000			564,000,000			10,000,000	12,000,000			554,000,000	578,000,000
Repurchased or otherwise settled mortgages																									194,000,000	137,000,000
Repurchased mortgage loans																									280,000,000		252,000,000	140,000,000	134,000,000
Amount funded by Visa into an escrow account to fund judgments and settlements relating to litigation																															8,100,000,000
Shares of Class B Visa Inc. common stock sold to another financial institution, shares																																											3.2
Shares of Class B Visa Inc. common stock sold to another financial institution, value																														112,000,000
Shares of Class B Visa Inc. common stock sold to another financial institution, recognized a gain																														112,000,000
Payments to derivative counterparty																															22,000,000	8,000,000	17,000,000
Derivative liability positions, fair value																															5,000,000	22,000,000				8,431,000,000	[1]	7,499,000,000	8,185,000,000	[1],[2]	7,309,000,000	[2]
Common stock conversion rate																														0.6296	0.4254
Tax Credits To Be Delivered																																		4,000,000	5,000,000
Loss Contingency, Range of Possible Loss, Minimum																					0
Loss Contingency, Range of Possible Loss, Maximum																					$ 600,000,000

[1] The Company offsets cash collateral paid to and received from derivative counterparties when the derivative contracts are subject to ISDA master netting arrangements and meet the derivative offsetting requirements. The effects of offsetting on the Company's Consolidated Balance Sheets as of March 31, 2012 are presented in Note 12, "Fair Value Election and Measurement."

[2] See “Economic Hedging and Trading Activities” in this Note for further discussion.