CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (USD $) In Millions, except Share data, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Balance at beginning of period at Dec. 31, 2011		$ 1,565
Balance at beginning of period, shares at Dec. 31, 2011		25,947,500	712
Balance at beginning of period at Dec. 31, 2011			0	13,814	2,481	642
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Excess of consideration received over book value on sale of London Branch precious metals business to an HSBC affiliate, net of tax				0
Capital contributions from parent				312
Employee benefit plans				(3)
Net income (loss)	(1,045)				(1,045)
Cash dividends declared on preferred stock					(73)
Adjustment to add other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity, net of tax	0					0
Other comprehensive income (loss), net of tax	143					143
Number of shares of common stock issued to parent			1
Balance at end of period at Dec. 31, 2012	17,836	1,565
Balance at end of period, shares at Dec. 31, 2012		25,947,500	713
Balance at end of period at Dec. 31, 2012	16,271		0	14,123	1,363	785
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Excess of consideration received over book value on sale of London Branch precious metals business to an HSBC affiliate, net of tax				0
Capital contributions from parent				0
Employee benefit plans				(17)
Net income (loss)	(338)				(338)
Cash dividends declared on preferred stock					(73)
Adjustment to add other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity, net of tax	(67)					(67)
Other comprehensive income (loss), net of tax	(877)					(877)
Number of shares of common stock issued to parent			0
Balance at end of period at Dec. 31, 2013	16,464	1,565
Balance at end of period, shares at Dec. 31, 2013		25,947,500	713
Balance at end of period at Dec. 31, 2013	14,899		0	14,106	952	(159)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Excess of consideration received over book value on sale of London Branch precious metals business to an HSBC affiliate, net of tax				60
Capital contributions from parent				0
Employee benefit plans				4
Net income (loss)	354				354
Cash dividends declared on preferred stock					(73)
Adjustment to add other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity, net of tax	0					0
Other comprehensive income (loss), net of tax	158					158
Number of shares of common stock issued to parent			0
Balance at end of period at Dec. 31, 2014	16,967	1,565
Balance at end of period, shares at Dec. 31, 2014		25,947,500	713
Balance at end of period at Dec. 31, 2014	$ 15,402		$ 0	$ 14,170	$ 1,233	$ (1)