Litigation and Regulatory Matters - Additional Information (Details)	1 Months Ended
	Oct. 31, 2015 USD ($)	Sep. 30, 2015 USD ($) complaint
Loss Contingencies [Line Items]
Estimate of loss		$ 100,000,000
Credit Default Swaps Antitrust Litigation [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		25,000,000
Foreign Exchange Class Action [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		$ 285,000,000
Number of putative class action complaints filed | complaint		2
Subsequent Event [Member] | Weller, et. al. v. HSBC Mortgage Services Inc., et. al. [Member]
Loss Contingencies [Line Items]
Litigation settlement amount	$ 1,800,000
Subsequent Event [Member] | Saber Ahmed v. HSBC Bank USA [Member]
Loss Contingencies [Line Items]
Damages sought, per violation (up to)	$ 1,500
HSBC Bank USA [Member] | Credit Default Swaps Antitrust Litigation [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		$ 12,500,000
HSBC Bank USA [Member] | Foreign Exchange Class Action [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		$ 14,250,000