Business Segment Information (Business Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Net interest income (expense)		$ 606	$ 549
Provision for credit losses		(13)	12
Noninterest income		238	244
Noninterest expenses		433	446
Provision (benefit) for income taxes		85	54
Net income (loss)		339	281
Net credit-related charge-offs (recoveries)		11	28
Assets, average		69,771	70,326
Loans, average		49,677	48,421
Deposits, average		$ 53,996	$ 56,090
Return on average assets	[1]	1.97%	1.62%
Efficiency ratio	[2]	50.81%	56.33%
Discrete tax benefits		$ 11	$ 22
Business Bank
Net interest income (expense)		412	381
Provision for credit losses		(6)	16
Noninterest income		136	131
Noninterest expenses		198	213
Provision (benefit) for income taxes		82	65
Net income (loss)		274	218
Net credit-related charge-offs (recoveries)		12	30
Assets, average		43,909	42,706
Loans, average		42,538	41,102
Deposits, average		$ 28,463	$ 30,485
Return on average assets	[1]	2.53%	2.07%
Efficiency ratio	[2]	36.23%	41.55%
Retail Bank
Net interest income (expense)		$ 146	$ 127
Provision for credit losses		(4)	(2)
Noninterest income		31	33
Noninterest expenses		145	148
Provision (benefit) for income taxes		8	3
Net income (loss)		28	11
Net credit-related charge-offs (recoveries)		0	0
Assets, average		2,812	2,632
Loans, average		2,103	2,073
Deposits, average		$ 20,470	$ 20,893
Return on average assets	[1]	0.54%	0.20%
Efficiency ratio	[2]	81.12%	92.16%
Wealth Management
Net interest income (expense)		$ 47	$ 43
Provision for credit losses		(5)	(4)
Noninterest income		64	67
Noninterest expenses		72	72
Provision (benefit) for income taxes		11	10
Net income (loss)		33	32
Net credit-related charge-offs (recoveries)		(1)	(2)
Assets, average		5,174	5,373
Loans, average		5,036	5,246
Deposits, average		$ 3,801	$ 3,796
Return on average assets	[1]	2.67%	2.42%
Efficiency ratio	[2]	64.41%	65.81%
Finance
Net interest income (expense)		$ (15)	$ (14)
Provision for credit losses		0	0
Noninterest income		4	11
Noninterest expenses		0	(1)
Provision (benefit) for income taxes		(4)	(3)
Net income (loss)		(7)	1
Net credit-related charge-offs (recoveries)		0	0
Assets, average		13,911	13,779
Loans, average		0	0
Deposits, average		1,130	823
Other
Net interest income (expense)		16	12
Provision for credit losses		2	2
Noninterest income		3	2
Noninterest expenses		18	14
Provision (benefit) for income taxes	[3]	(12)	(21)
Net income (loss)		11	19
Net credit-related charge-offs (recoveries)		0	0
Assets, average		3,965	5,836
Loans, average		0	0
Deposits, average		$ 132	$ 93

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

[3] Included discrete tax benefits of $11 million and $22 million for the three months ended March 31, 2019 and 2018, respectively.