Guarantee Arrangements and Pledged Assets - Outstanding Repurchase Demands Received From GSEs and Other Third Parties (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
GSEs	$ 74		$ 86
Others	4		3
Total	$ 78	[1]	$ 89	[2]

[1] Includes repurchase demands on loans sourced from our legacy broker channel of $64 million and $65 million at March 31, 2013 and December 31, 2012, respectively.

[2] 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.