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	Mar. 31, 2013		Dec. 31, 2012
Guarantor Obligations [Line Items]
Carrying Value	$ (621)		$ (76)
Notional/Maximum Exposure to Loss	239,772		248,192
Credit derivatives [Member]
Guarantor Obligations [Line Items]
Carrying Value	(621)	[1],[2]	(76)	[1],[2]
Notional/Maximum Exposure to Loss	229,166	[1],[2]	237,548	[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	5,405	[3],[4]	5,554	[3],[4]
Performance (non-financial) guarantees [Member]
Guarantor Obligations [Line Items]
Carrying Value	0	[3]	0	[3]
Notional/Maximum Exposure to Loss	2,747	[3]	2,878	[3]
Liquidity asset purchase agreements [Member]
Guarantor Obligations [Line Items]
Carrying Value	0	[3]	0	[3]
Notional/Maximum Exposure to Loss	$ 2,454	[3]	$ 2,212	[3]

[1] Includes $42.4 billion and $44.2 billion of notional issued for the benefit of HSBC affiliates at March 31, 2013 and December 31, 2012, respectively.

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

[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 $840 million and $808 million issued for the benefit of HSBC affiliates at March 31, 2013 and December 31, 2012, respectively.