Related Party Transactions - Schedule of due to Affiliated entities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Due to affiliates	$ 6,940	$ 8,742
Due to affiliate, carried at fair value	506	496
HSBC Private Banking Holdings (Suisse) S.A and subsidiaries [Member]
Related Party Transaction [Line Items]
Due to affiliates	2,500	4,300
HSBC USA, Inc. [Member]
Related Party Transaction [Line Items]
Due to affiliates	3,012	3,012
HSBC Holdings pcl [Member]
Related Party Transaction [Line Items]
Due to affiliates	828	820
HSBC North America [Member]
Related Party Transaction [Line Items]
Due to affiliates	600	600
HSBC Asia [Member]
Related Party Transaction [Line Items]
Due to affiliates	$ 0	$ 10