Financial Statements of HSBC USA Inc. (Parent) Statement of Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Income:
Other interest income									$ 43		$ 59	$ 41
Other securities gains, net									70		48	113
Total income									3,444		3,781	3,722
Expenses:
Other Interest Expense									15		16	(88)
Provision for credit losses	$ 19	$ 62	$ 134	$ 157	$ 267	$ 47	$ (6)	$ 53	372	[1]	361	188
Income before income tax	(48)	59	(26)	233	(180)	315	185	240	218		560	298
Income tax benefit	11	(26)	5	(79)	55	(111)	(98)	(76)	(89)		(230)	56
Net income	$ (37)	$ 33	$ (21)	$ 154	$ (125)	$ 204	$ 87	$ 164	129		330	354
HSBC USA Inc [Member]
Income:
Dividends from banking subsidiaries									136		104	0
Dividends from other subsidiaries									17		1	1
Interest from subsidiaries									268		97	66
Interest from other HSBC affiliates									115		121	117
Other interest income									2		14	22
Other securities gains, net									7		1	0
Other income from subsidiaries									1		(2)	(1)
Other income from other HSBC Affiliates									418		(79)	395
Other income (loss)									(321)		121	(347)
Total income									643		378	253
Expenses:
Interest to subsidiaries									0		23	45
Interest to other HSBC Affiliates									43		28	49
Other Interest Expense									475		375	266
Provision for credit losses									0		0	(3)
Other expenses with subsidiaries									27		0	23
Other expenses									3		6	182
Total expenses									548		432	562
Income before income tax									95		(54)	(309)
Income tax benefit									27		76	107
Income (loss) before equity in undistributed income of subsidiaries									122		22	(202)
Equity in undistributed income of subsidiaries									7		308	556
Net income									$ 129		$ 330	$ 354

[1] The provision for credit losses and charge-offs for residential mortgage loans during 2016 includes $11 million related to the lower of amortized cost or fair value adjustment attributable to credit factors for loans transferred to held for sale. See Note 7, "Loans Held for Sale," for additional information.