Business Segments 1 - Group Reporting Basis to US GAAP Adjustments from previous table (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income	[1]	$ 2,387	$ 2,471		$ 2,317
Group Reporting Basis Other revenues	[2]	1,727	1,595		2,010
Group Reporting Basis Provision for credit losses		(119)	494		264
Group Reporting Basis Operating expenses	[2]	3,333	3,278	[3]	3,308	[3]
Group Reporting Basis Profit (Loss) Before Income Tax Expense		900	294		755
Group Reporting Basis Total assets		220,313	246,506		234,530
Derivatives [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0	0		0
Group Reporting Basis Other revenues		0	0		(3)
Group Reporting Basis Provision for credit losses		0	0		0
Group Reporting Basis Operating expenses		0	0		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		0	0		(3)
Group Reporting Basis Total assets		(32,900)	(44,911)		(46,245)
Goodwill [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0	0		0
Group Reporting Basis Other revenues		(1)	0		0
Group Reporting Basis Provision for credit losses		0	0		0
Group Reporting Basis Operating expenses		0	0		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(1)	0		0
Group Reporting Basis Total assets		347	348		348
Litigation [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		8	(8)		(2)
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(8)	8		2
Group Reporting Basis Total assets		0	(3)		0
Loan Impairment [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		(43)	(57)		(61)
Group Reporting Basis Other revenues		0	7		3
Group Reporting Basis Provision for credit losses		(72)	(58)		132
Group Reporting Basis Operating expenses		0	1		1
Group Reporting Basis Profit (Loss) Before Income Tax Expense		29	7		(191)
Group Reporting Basis Total assets		(332)	(326)		(329)
Loan Origination [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		(19)	(21)		(22)
Group Reporting Basis Other revenues		0	0		(3)
Group Reporting Basis Provision for credit losses		0	0		0
Group Reporting Basis Operating expenses		(14)	(19)		(47)
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(5)	(2)		22
Group Reporting Basis Total assets		42	35		49
Loans Held for Sale [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		9	0		0
Group Reporting Basis Other revenues		141	(80)		(16)
Group Reporting Basis Provision for credit losses		0	(20)		(2)
Group Reporting Basis Operating expenses		0	0		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		150	(60)		(14)
Group Reporting Basis Total assets		21	(31)		(4)
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		(7)	(9)		(12)
Group Reporting Basis Provision for credit losses		0	0		0
Group Reporting Basis Operating expenses		0	0		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(7)	(9)		(12)
Group Reporting Basis Total assets		0	0		0
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		94	19		15
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(94)	(19)		(15)
Group Reporting Basis Total assets		(263)	(191)		(177)
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		(11)	(19)		(19)
Group Reporting Basis Profit (Loss) Before Income Tax Expense		11	19		19
Group Reporting Basis Total assets		8	16		21
Structured Notes and Deposits [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		0
Group Reporting Basis Other revenues		85
Group Reporting Basis Provision for credit losses		0
Group Reporting Basis Operating expenses		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		85
Group Reporting Basis Total assets		0
Unquoted Equity Securities [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 Profit (Loss) Before Income Tax Expense			0		0
Group Reporting Basis Total assets			(163)		(228)
Other [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income		5	2		5
Group Reporting Basis Other revenues		(18)	(22)		(8)
Group Reporting Basis Provision for credit losses		0	0		0
Group Reporting Basis Operating expenses		(2)	0		0
Group Reporting Basis Profit (Loss) Before Income Tax Expense		(11)	(20)		(3)
Group Reporting Basis Total assets		(1)	(8)		(4)
Group Reporting Basis Adjustments [Member]
Segment Reporting Information [Line Items]
Group Reporting Basis Net interest income	[1],[4]	(48)	(76)		(78)
Group Reporting Basis Other revenues	[2],[4]	200	(104)		(39)
Group Reporting Basis Provision for credit losses	[4]	(72)	(78)		130
Group Reporting Basis Operating expenses	[2],[4]	75	(26)	[3]	(52)	[3]
Group Reporting Basis Profit (Loss) Before Income Tax Expense	[4]	149	(76)		(195)
Group Reporting Basis Total assets	[4]	$ (33,078)	$ (45,234)		$ (46,569)

[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 the segments.

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

[3] In 2017, we changed our presentation for certain cost reimbursements that were previously netted as an offset to affiliate expense. We now present these reimbursements gross in affiliate income. As a result, we have reclassified prior year amounts in order to conform to the current year presentation, which increased both RBWM other operating income and RBWM operating expenses $11 million during the year ended December 31, 2016 and also increased both GB&M other operating income and GB&M operating expenses $61 million and $63 million during the years ended December 31, 2016 and 2015, respectively. See Note 21, "Related Party Transactions," in the accompanying consolidated financial statements for additional information.

[4] Represents adjustments associated with differences between U.S. GAAP and the Group Reporting Basis. These adjustments, which are more fully described above, consist of the following: NetInterestIncome OtherRevenues Provisionfor CreditLosses OperatingExpenses Profit (Loss)before IncomeTax Expense TotalAssets (in millions)December 31, 2017 Derivatives$— $— $— $— $— $(32,900)Goodwill— (1) — — (1) 347Litigation— — — 8 (8) —Loan impairment(43) — (72) — 29 (332)Loan origination(19) — — (14) (5) 42Loans held for sale9 141 — — 150 21Low income housing tax credit investments— (7) — — (7) —Pension and other postretirement benefit costs— — — 94 (94) (263)Property— — — (11) 11 8Structured notes and deposits— 85 — — 85 —Other5 (18) — (2) (11) (1)Total adjustments$(48) $200 $(72) $75 $149 $(33,078) December 31, 2016 Derivatives$— $— $— $— $— $(44,911)Goodwill— — — — — 348Litigation— — — (8) 8 (3)Loan impairment(57) 7 (58) 1 7 (326)Loan origination(21) — — (19) (2) 35Loans held for sale— (80) (20) — (60) (31)Low income housing tax credit investments— (9) — — (9) —Pension and other postretirement benefit costs— — — 19 (19) (191)Property— — — (19) 19 16Unquoted equity securities— — — — — (163)Other2 (22) — — (20) (8)Total adjustments$(76) $(104) $(78) $(26) $(76) $(45,234) December 31, 2015 Derivatives$— $(3) $— $— $(3) $(46,245)Goodwill— — — — — 348Litigation— — — (2) 2 —Loan impairment(61) 3 132 1 (191) (329)Loan origination(22) (3) — (47) 22 49Loans held for sale— (16) (2) — (14) (4)Low income housing tax credit investments— (12) — — (12) —Pension and other postretirement benefit costs— — — 15 (15) (177)Property— — — (19) 19 21Unquoted equity securities— — — — — (228)Other5 (8) — — (3) (4)Total adjustments$(78) $(39) $130 $(52) $(195) $(46,569)