Long-Term Debt-Additional Information (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended							12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Junior subordinated debt [Member]	Dec. 31, 2013 Junior subordinated debt [Member] capital_funding_trust	Dec. 31, 2013 Medium-term Notes [Member]	Dec. 31, 2012 Medium-term Notes [Member]	Dec. 31, 2013 Subordinated Debt [Member]	Dec. 31, 2012 Subordinated Debt [Member]	Dec. 31, 2013 HSBC Bank USA and its Subsidiaries [Member]	Dec. 31, 2012 HSBC Bank USA and its Subsidiaries [Member]	Dec. 31, 2013 HSBC USA Inc [Member] 5 year Senior Notes Due 2018 (1.26% - 2.625%) [Member] Senior Notes [Member]	Dec. 31, 2013 HSBC USA Inc [Member] 5 year Senior Notes due 2018 (1.26%-2.625%) [Member] Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt due from subsidiaries										$ 900,000,000	$ 900,000,000
Long-term debt carried at fair value						5,700,000,000	5,300,000,000	1,900,000,000	2,000,000,000
Debt term												5 years	5 years
Number of capital funding trusts holding long-term debt					3
Face amount of original repurchased debt				309,000,000
Contractual call price				103.925%
Net loss on extinguishment				(12,000,000)
Number of shares of common stock issued to parent				1
Capital contribution from parent	$ 0	$ 312,000,000	$ 0	$ 312,000,000