Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified			0 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 29, 2013 Insurance business	Mar. 31, 2013 Insurance business	Dec. 31, 2012 Insurance business	Jun. 30, 2012 Card and Retail Services	May 02, 2012 Card and Retail Services	Mar. 31, 2013 HSBC USA, Inc. [Member] Card and Retail Services	Mar. 31, 2012 HSBC USA, Inc. [Member] Card and Retail Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain				$ 23		$ 2,200
After-tax gain				15		1,400
Lower of amortized cost or fair value less cost to sell adjustment, before tax					119
Lower of amortized cost or fair value less cost to sell adjustment, after tax					90
Sold business, premium percentage of receivables							8.75%
Proceeds from divestiture of businesses			155			11,800
Gain on sale of intangible assets									79
Incremental increase in industry review enhancement expense								100
Other Liabilities for enhancement services products	$ 159	$ 59