Long-Term Debt - Additional Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Senior Notes [Member]	Sep. 30, 2012 Senior Notes [Member]	Dec. 31, 2013 Delayed Draw Term Loan [Member] HSBC North America [Member] borrowing	Dec. 31, 2013 Trust Preferred Securities Subject to Mandatory Redemption [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] Amended Credit Agreement [Member] HSBC USA, Inc. [Member]
Debt Instrument [Line Items]
Cumulative carrying value adjustments on derivative financial instruments	$ 5	$ 17
Change in carrying value of foreign debt resulting from translation adjustments	484	828
Long-term debt	8,025	9,725
Interest Expense for long-term debt for continuing operations	1,141	1,585	2,166
Weighted average interest rate on long-term debt	4.35%	4.48%
Repurchased face amount				102	512
Long-term debt due to affiliate								512
Loan agreements with affiliates						600	1,000
Number of draws allowed						3
Amount per draw						200
Long-term debt collateralized by receivables	2,200	2,878
Loans pledged as collateral	$ 4,020	$ 4,898
Preferred Stock callable at par (usd per share)							$ 25
Preferred Securities have a liquidation value per preferred security (usd per share)							$ 25