Financial Statements of HSBC USA Inc. (Parent) Statement of Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income:
Other interest income									$ 41	$ 41	$ 43
Other securities gains, net									113	202	145
Other income									84	59	58
Total income									3,722	3,705	3,838
Expenses:
Other Interest Expense									(101)	53	33
Provision for credit losses	64	23	85	16	51	54	67	21	188	193	293
Goodwill impairment									0	616	0
Income (loss) from continuing operations before income tax	100	(28)	(27)	253	(777)	36	251	308	298	(182)	(826)
Income tax benefit	(30)	29	206	(149)	72	(32)	(71)	(125)	56	(156)	(422)
Net income (loss)	70	1	179	104	(705)	4	180	183	354	(338)	(1,045)
HSBC USA Inc [Member]
Income:
Dividends from other subsidiaries									1	1	57
Interest from subsidiaries									66	67	67
Interest from other HSBC affiliates									117	95	27
Other interest income									22	22	19
Other securities gains, net									0	0	21
Other income from subsidiaries									(1)	276	(301)
Other income from other HSBC Affiliates									395	543	472
Other income									(347)	(799)	(144)
Total income									253	205	218
Expenses:
Interest to subsidiaries									45	45	69
Interest to other HSBC Affiliates									49	59	65
Other Interest Expense									266	231	198
Provision for credit losses									(3)	0	0
Goodwill impairment									0	510	0
Other expenses with subsidiaries									23	0	0
Other expenses with Other HSBC Affiliates									0	0	19
Other expenses									182	124	8
Total expenses									562	969	359
Income (loss) from continuing operations before income tax									(309)	(764)	(141)
Income tax benefit									107	101	47
Loss before equity in undistributed income of subsidiaries									(202)	(663)	(94)
Equity in undistributed income (loss) of subsidiaries									556	325	(951)
Net income (loss)									$ 354	$ (338)	$ (1,045)