Guarantees - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	9 Months Ended		12 Months Ended				117 Months Ended			117 Months Ended	9 Months Ended	12 Months Ended			117 Months Ended							3 Months Ended	9 Months Ended					1 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009	Sep. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014 Ginnie Mae [Member]	Sep. 30, 2014 Non Government Sponsored Agency [Member]	Dec. 31, 2013 Non Government Sponsored Agency [Member]	Dec. 31, 2012 Non Government Sponsored Agency [Member]	Dec. 31, 2011 Non Government Sponsored Agency [Member]	Sep. 30, 2014 Non Government Sponsored Agency [Member]	Sep. 30, 2014 US Government Sponsored Agency [Member]	Dec. 31, 2013 US Government Sponsored Agency [Member]	Sep. 30, 2014 Standby Letters of Credit	Dec. 31, 2013 Standby Letters of Credit	Sep. 30, 2014 Mortgage Servicing Rights [Member]	Dec. 31, 2013 Mortgage Servicing Rights [Member]	Sep. 30, 2014 Visa Interest [Member]	Sep. 30, 2013 Visa Interest [Member]	Dec. 31, 2013 Visa Interest [Member]	May 31, 2009 Visa Interest [Member]	Sep. 30, 2014 Tax Credit Sales [Member]	Dec. 31, 2013 Tax Credit Sales [Member]	May 31, 2009 Not Designated as Hedging Instrument [Member] Derivative Financial Instruments, Liabilities [Member] Visa Interest [Member]	Sep. 30, 2014 Residential Mortgage, Loans Held For Sale [Member]	Dec. 31, 2013 Residential Mortgage, Loans Held For Sale [Member]	Sep. 30, 2014 Residential Mortgage, Loans Held For Sale [Member] Nonperforming Financing Receivable [Member]	Dec. 31, 2013 Residential Mortgage, Loans Held For Sale [Member] Nonperforming Financing Receivable [Member]	Sep. 30, 2014 Loans Held For Investment [Member]	Dec. 31, 2013 Loans Held For Investment [Member]	Sep. 30, 2014 Loans Held For Investment [Member] Nonperforming Financing Receivable [Member]	Dec. 31, 2013 Loans Held For Investment [Member] Nonperforming Financing Receivable [Member]
Loans sold from January 1, 2005 to June 30, 2014								$ 307,300,000,000			$ 30,200,000,000					$ 36,000,000,000	$ 241,100,000,000
Loans Sold Repurchased Request Amount		139,000,000		1,500,000,000	1,700,000,000	1,700,000,000		8,600,000,000				1,000,000	18,000,000	22,000,000	50,000,000
Unpaid principal balance of loans related to unresolved requests previously received from investors	45,000,000	45,000,000		126,000,000				45,000,000				3,000,000	4,000,000			3,000,000	42,000,000	122,000,000
Mortgage Repurchase Reserve, Provision for Mortgage Loan Repurchase Losses	2,000,000	12,000,000
Reserve For Mortgage Loan Repurchase Losses	77,000,000	77,000,000	281,000,000	78,000,000	632,000,000			77,000,000	77,000,000	363,000,000
Repurchased or otherwise settled mortgages		23,000,000	800,000,000
Repurchased mortgage loans	325,000,000	325,000,000		339,000,000				325,000,000																						7,000,000	14,000,000	7,000,000	14,000,000	318,000,000	325,000,000	48,000,000	54,000,000
Loss Contingency Accrual, at Carrying Value																					26,000,000	21,000,000
Business Combination, Contingent Consideration, Liability	24,000,000	24,000,000		26,000,000				24,000,000
Third Party Escrow, Gross Funded Since Inception																							8,500,000,000
Third Party Escrow, Amount Paid From Escrow																							7,000,000,000
Third Party Escrow, Current Balance																							1,500,000,000
Number Of Shares Sold To Selected Financial Institutions																													3.2
Shares of Class B Visa Inc Common Stock Sold to Another FinancialIinstitution, Value							112,000,000
Gain (Loss) on Sale of Other Investments							112,000,000
Common stock conversion rate																							0.4121			0.6296
Visa Share of Claims in Settlement Agreement Amount																							4,400,000,000
Third Party Escrow Deposit																							450,000,000	1,000,000,000
Derivative Liability, Current																							11,000,000		2,000,000
Maximum potential amount obligation																			3,200,000,000	3,300,000,000							19,000,000
Tax Credits To Be Delivered																											$ 1,000,000	$ 1,000,000