Guarantees and Contingent Liabilities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Guarantees And Contingent Liabilities Textual [Abstract]
Liability related to remaining Visa Litigation, carrying amount	$ 65
Value of airline tickets purchased to deliver at a future date	7,800
Company held collateral in escrow deposits, letters of credit and indemnities from financial institutions, and liens on various assets	759
Representation and warranty reserve	190	233	240	216	202	160
Unresolved representation and warranty claims	64		131
Loss contingency range of possible loss maximum	$ 200