Business Segment Information (Business Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Net interest income (expense)		$ 544	$ 586	$ 603	$ 606	$ 614	$ 599	$ 549	$ 590	$ 2,339		$ 2,352		$ 2,061
Provision for credit losses										74		(1)		74
Noninterest income										1,010		976		1,107
Noninterest expenses		451	435	424	433	448	452	446	448	1,743		1,794		1,860
Provision (benefit) for income taxes		(82)	(80)	(87)	(85)	(90)	(63)	(54)	(93)	(334)		(300)		(491)
Net income (loss)		$ 269	$ 292	$ 298	$ 339	$ 310	$ 318	$ 281	$ 326	1,198		1,235		743
Net loan charge-offs (recoveries)										107		51		92
Assets, average										71,488		70,724		71,452
Loans, average										50,511		48,766		48,558
Deposits, average										$ 55,481		$ 55,935		$ 57,258
Return on average assets	[1]									1.68%		1.75%		1.04%
Efficiency ratio	[2]									51.82%		53.56%		58.70%
Business Bank
Net interest income (expense)										$ 1,655		$ 1,613		$ 1,513
Provision for credit losses										88		6		69
Noninterest income										555		547		639
Noninterest expenses										795		847		918
Provision (benefit) for income taxes										(306)		(283)		(410)
Net income (loss)										1,021		1,024		755
Net loan charge-offs (recoveries)										111		52		96
Assets, average										44,946		43,207		42,653
Loans, average										43,472		41,618		41,241
Deposits, average										$ 29,047		$ 30,116		$ 31,999
Return on average assets	[1]									2.27%		2.37%		1.77%
Efficiency ratio	[2]									35.96%		39.22%		42.67%
Retail Bank
Net interest income (expense)										$ 568		$ 548		$ 453
Provision for credit losses										(4)		(1)		2
Noninterest income										132		136		154
Noninterest expenses										597		602		615
Provision (benefit) for income taxes										(24)		(18)		4
Net income (loss)										83		65		(6)
Net loan charge-offs (recoveries)										1		0		1
Assets, average										2,852		2,633		2,626
Loans, average										2,104		2,067		2,061
Deposits, average										$ 20,743		$ 20,812		$ 20,775
Return on average assets	[1]									0.39%		0.31%		(0.03%)
Efficiency ratio	[2]									84.49%		87.59%		101.29%
Wealth Management
Net interest income (expense)										$ 183		$ 181		$ 169
Provision for credit losses										(14)		(3)		1
Noninterest income										270		266		255
Noninterest expenses										283		293		285
Provision (benefit) for income taxes										(44)		(36)		(51)
Net income (loss)										140		121		87
Net loan charge-offs (recoveries)										(5)		(1)		(5)
Assets, average										5,083		5,214		5,401
Loans, average										4,935		5,081		5,256
Deposits, average										$ 3,833		$ 3,941		$ 4,081
Return on average assets	[1]									2.76%		2.32%		1.61%
Efficiency ratio	[2]									62.45%		65.60%		67.06%
Finance
Net interest income (expense)										$ (126)		$ (46)		$ (111)
Provision for credit losses										0		0		0
Noninterest income										43		27		49
Noninterest expenses										(1)		(4)		(4)
Provision (benefit) for income taxes										26		14		35
Net income (loss)										(56)		(1)		(23)
Net loan charge-offs (recoveries)										0		0		0
Assets, average										14,235		13,705		13,954
Loans, average										0		0		0
Deposits, average										1,673		941		241
Other
Net interest income (expense)										59		56		37
Provision for credit losses										4		(3)		2
Noninterest income										10		0		10
Noninterest expenses										69		56		46
Provision (benefit) for income taxes										14	[3]	23	[3]	(69)
Net income (loss)										10		26		(70)
Net loan charge-offs (recoveries)										0		0		0
Assets, average										4,372		5,965		6,818
Loans, average										0		0		0
Deposits, average										$ 185		$ 125		$ 162

[1] Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.

[2] Noninterest expenses as a percentage of the sum of net interest income and noninterest income excluding net gains (losses) from securities and a derivative contract tied to the conversion rate of Visa Class B shares.

[3] Primarily reflected discrete tax items, including benefits of $17 million and $48 million in 2019 and 2018, respectively, and a net charge of $72 million in 2017.