Pensions and Other Postretirement Benefits-Net Periodic Benefit Cost (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Postretirement Plans Other Than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	$ 1	$ 1	$ 1
Interest cost on projected benefit obligation	2	3	4
Amortization of transition obligation	0	2	2
Net periodic benefit cost	3	6	7
HSBC USA Inc [Member] | HSBC North America Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	4	15	14
Interest cost on projected benefit obligation	71	67	74
Expected return on assets	(83)	(91)	(81)
Amortization of prior service cost (benefit)	0	(5)	(6)
Recognized losses	49	46	38
Curtailment benefit recognized	0	(31)	0
Net periodic benefit cost	$ 41	$ 1	$ 39