Business Segment Information (Business Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Net interest income (expense)		$ 513	$ 606
Provision for credit losses		411	(13)
Noninterest income		237	238
Noninterest expenses		425	433
(Benefit) provision for income taxes		(21)	85
Net (loss) income		(65)	339
Net credit-related charge-offs (recoveries)		84	11
Assets, average		73,265	69,771
Loans, average		49,604	49,677
Deposits, average		$ 56,768	$ 53,996
Return on average assets	[1]	(0.35%)	1.97%
Efficiency ratio	[2]	56.57%	50.81%
Business Bank
Net interest income (expense)		$ 380	$ 412
Provision for credit losses		396	(6)
Noninterest income		127	136
Noninterest expenses		194	198
(Benefit) provision for income taxes		(20)	82
Net (loss) income		(63)	274
Net credit-related charge-offs (recoveries)		83	12
Assets, average		44,254	43,909
Loans, average		42,593	42,538
Deposits, average		$ 30,230	$ 28,463
Return on average assets	[1]	(0.58%)	2.53%
Efficiency ratio	[2]	38.47%	36.24%
Retail Bank
Net interest income (expense)		$ 125	$ 146
Provision for credit losses		3	(4)
Noninterest income		28	31
Noninterest expenses		149	145
(Benefit) provision for income taxes		0	8
Net (loss) income		1	28
Net credit-related charge-offs (recoveries)		1	0
Assets, average		2,864	2,812
Loans, average		2,075	2,103
Deposits, average		$ 21,195	$ 20,470
Return on average assets	[1]	0.03%	0.54%
Efficiency ratio	[2]	96.03%	81.34%
Wealth Management
Net interest income (expense)		$ 41	$ 48
Provision for credit losses		12	(5)
Noninterest income		70	64
Noninterest expenses		72	72
(Benefit) provision for income taxes		6	11
Net (loss) income		21	34
Net credit-related charge-offs (recoveries)		0	(1)
Assets, average		5,078	5,174
Loans, average		4,936	5,036
Deposits, average		$ 4,025	$ 3,801
Return on average assets	[1]	1.69%	2.67%
Efficiency ratio	[2]	64.28%	64.42%
Finance
Net interest income (expense)		$ (44)	$ (15)
Provision for credit losses		0	0
Noninterest income		14	3
Noninterest expenses		0	0
(Benefit) provision for income taxes		(8)	(4)
Net (loss) income		(22)	(8)
Net credit-related charge-offs (recoveries)		0	0
Assets, average		14,285	13,585
Loans, average		0	0
Deposits, average		1,136	1,130
Other
Net interest income (expense)		11	15
Provision for credit losses		0	2
Noninterest income		(2)	4
Noninterest expenses		10	18
(Benefit) provision for income taxes	[3]	1	(12)
Net (loss) income		(2)	11
Net credit-related charge-offs (recoveries)		0	0
Assets, average		6,784	4,291
Loans, average		0	0
Deposits, average		$ 182	$ 132

[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 (losses) gains from securities and a derivative contract tied to the conversion rate of Visa Class B shares.

[3] Included discrete tax benefits of $3 million and $11 million for the three months ended March 31, 2020 and 2019, respectively.