Business Segments 1 - Group Reporting Basis to US GAAP Adjustments from previous table (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Unquoted Equity Securities [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		$ 0		$ 0		$ 0
Group Reporting Basis Other revenues		0		0		0
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		0		0		0
Group Reporting Basis Income (loss) from continuing operations before income tax		0		0		0
Group Reporting Basis Total assets		(228)		(195)		(163)
Reclassification of Financial Assets [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		(8)		(10)		(14)
Group Reporting Basis Other revenues		6		8		40
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		0		0		0
Group Reporting Basis Income (loss) from continuing operations before income tax		(2)		(2)		26
Group Reporting Basis Total assets		7		11		11
Securities (Assets) [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0		0
Group Reporting Basis Other revenues		0		0		(1)
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		(1)		(3)		(2)
Group Reporting Basis Income (loss) from continuing operations before income tax		1		3		1
Group Reporting Basis Total assets		(7)		(13)		(24)
Derivatives [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0		0
Group Reporting Basis Other revenues		(3)		(4)		(3)
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		0		0		0
Group Reporting Basis Income (loss) from continuing operations before income tax		(3)		(4)		(3)
Group Reporting Basis Total assets		(46,245)		(53,973)		(49,876)
Loan Impairment [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		(61)		(56)		(57)
Group Reporting Basis Other revenues		3		1		1
Group Reporting Basis Provision for credit losses		132		120		(11)
Group Reporting Basis Operating expenses		1		1		1
Group Reporting Basis Income (loss) from continuing operations before income tax		(191)		(176)		(46)
Group Reporting Basis Total assets		(329)		(204)		(94)
Property [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0		0
Group Reporting Basis Other revenues		0		0		0
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		(19)		(16)		(17)
Group Reporting Basis Income (loss) from continuing operations before income tax		19		16		17
Group Reporting Basis Total assets		21		28		37
Pension and Other Postretirement Benefit Costs [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0		0
Group Reporting Basis Other revenues		0		0		0
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		15		11		24
Group Reporting Basis Income (loss) from continuing operations before income tax		(15)		(11)		(24)
Group Reporting Basis Total assets		(177)		(166)		(154)
Goodwill [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0
Group Reporting Basis Other revenues		0		0
Group Reporting Basis Provision for credit losses		0		0
Group Reporting Basis Operating expenses		0		0
Group Reporting Basis Income (loss) from continuing operations before income tax		0		0
Group Reporting Basis Total assets		348		348
Litigation [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0
Group Reporting Basis Other revenues		0		0
Group Reporting Basis Provision for credit losses		0		0
Group Reporting Basis Operating expenses		(2)		(135)
Group Reporting Basis Income (loss) from continuing operations before income tax		2		135
Group Reporting Basis Total assets		0		1
Loan Origination [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		(22)
Group Reporting Basis Other revenues		(3)
Group Reporting Basis Provision for credit losses		0
Group Reporting Basis Operating expenses		(47)
Group Reporting Basis Income (loss) from continuing operations before income tax		22
Group Reporting Basis Total assets		49
Loans Held for Sale [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0
Group Reporting Basis Other revenues		(16)
Group Reporting Basis Provision for credit losses		(2)
Group Reporting Basis Operating expenses		0
Group Reporting Basis Income (loss) from continuing operations before income tax		(14)
Group Reporting Basis Total assets		(4)
Sale of London Branch Precious Metals Business [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income				0
Group Reporting Basis Other revenues				(98)
Group Reporting Basis Provision for credit losses				0
Group Reporting Basis Operating expenses				0
Group Reporting Basis Income (loss) from continuing operations before income tax				(98)
Group Reporting Basis Total assets				0
Goodwill Impairment [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income						0
Group Reporting Basis Other revenues						0
Group Reporting Basis Provision for credit losses						0
Group Reporting Basis Operating expenses						135
Group Reporting Basis Income (loss) from continuing operations before income tax						(135)
Group Reporting Basis Total assets						348
Low Income Housing Tax Credit [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0		0		0
Group Reporting Basis Other revenues		(12)		(16)		(30)
Group Reporting Basis Provision for credit losses		0		0		0
Group Reporting Basis Operating expenses		0		0		0
Group Reporting Basis Income (loss) from continuing operations before income tax		(12)		(16)		(30)
Group Reporting Basis Total assets		0		0		0
Other [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		13		(8)		(5)
Group Reporting Basis Other revenues		(14)		(23)		15
Group Reporting Basis Provision for credit losses		0		(40)		11
Group Reporting Basis Operating expenses		1		(16)		60
Group Reporting Basis Income (loss) from continuing operations before income tax		(2)		25		(61)
Group Reporting Basis Total assets		(4)		25		36
Group Reporting Basis Adjustments [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income	[1]	(78)	[2]	(74)	[2]	(76)
Group Reporting Basis Other revenues		(39)	[2]	(132)	[2]	22
Group Reporting Basis Provision for credit losses		130	[2]	80	[2]	0
Group Reporting Basis Operating expenses	[3]	(52)	[2]	(158)	[2]	201
Group Reporting Basis Income (loss) from continuing operations before income tax		(195)	[2]	(128)	[2]	(255)
Group Reporting Basis Total assets		$ (46,569)	[2]	$ (54,138)	[2]	$ (49,879)

[1] Net interest income of each segment represents the difference between actual interest earned on assets and interest paid on liabilities of the segment adjusted for a funding charge or credit. Segments are charged a cost to fund assets (e.g. customer loans) and receive a funding credit for funds provided (e.g. customer deposits) based on equivalent market rates. The objective of these charges/credits is to transfer interest rate risk from the segments to one centralized unit in Balance Sheet Management and more appropriately reflect the profitability of segments.

[2] Represents adjustments associated with differences between the Group Reporting Basis and the U.S. GAAP basis of accounting.

[3] Expenses for the segments include fully apportioned corporate overhead expenses.