Guarantee Arrangements and Pledged Assets - Carrying Value and Contractual Amounts of our Sell Protection Credit Derivatives and Major Off-Balance Sheet Guarantee Arrangements (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Guarantor Obligations [Line Items]
Carrying Value	$ (76)		$ (7,759)
Notional/Maximum Exposure to Loss	248,192		338,865
Credit derivatives [Member]
Guarantor Obligations [Line Items]
Carrying Value	(76)		(7,759)	[1],[2]
Notional/Maximum Exposure to Loss	237,548		330,395	[1],[2]
Financial standby letters of credit, net of participations [Member]
Guarantor Obligations [Line Items]
Carrying Value	0	[3],[4]	0	[3],[4]
Notional/Maximum Exposure to Loss	5,554	[3],[4]	4,705	[3],[4]
Performance (non-financial) guarantees [Member]
Guarantor Obligations [Line Items]
Carrying Value	0	[3]	0	[3]
Notional/Maximum Exposure to Loss	2,878	[3]	3,088	[3]
Liquidity asset purchase agreements [Member]
Guarantor Obligations [Line Items]
Carrying Value	0	[3]	0	[3]
Notional/Maximum Exposure to Loss	$ 2,212	[3]	$ 677	[3]

[1] For credit derivatives, the maximum loss is represented by the notional amounts without consideration of mitigating effects from collateral or recourse arrangements.

[2] Includes $44.2 billion and $45.1 billion of notional issued for the benefit of HSBC affiliates at December 31, 2012 and 2011, respectively.

[3] For standby letters of credit and liquidity asset purchase agreements, maximum loss represents losses to be recognized assuming the letter of credit and liquidity facilities have been fully drawn and the obligors have defaulted with zero recovery.

[4] Includes $808 million and $707 million issued for the benefit of HSBC affiliates at December 31, 2012 and 2011, respectively.