Business Segment Information (Business Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net interest income (expense)		$ 471	$ 603	$ 984	$ 1,209
Provision for credit losses		138	44	549	31
Noninterest income		247	250	484	488
Noninterest expenses		440	424	865	857
(Benefit) provision for income taxes		27	87	6	172
Net income		113	298	48	637
Net credit-related charge-offs (recoveries)		50	33	134	44
Assets, average		81,644	71,252	77,454	70,515
Loans, average		53,498	50,963	51,551	50,323
Deposits, average		$ 64,282	$ 54,995	$ 60,524	$ 54,498
Return on average assets	[1]	0.55%	1.68%	0.12%	1.82%
Efficiency ratio	[2]	61.14%	49.65%	58.80%	50.23%
Commercial Bank
Net interest income (expense)		$ 402	$ 420	$ 782	$ 832
Provision for credit losses		117	52	513	46
Noninterest income		144	136	271	272
Noninterest expenses		207	195	401	393
(Benefit) provision for income taxes		47	71	27	153
Net income		175	238	112	512
Net credit-related charge-offs (recoveries)		48	35	131	47
Assets, average		47,392	45,321	45,823	44,619
Loans, average		45,914	43,932	44,253	43,241
Deposits, average		$ 36,318	$ 28,251	$ 33,274	$ 28,356
Return on average assets	[1]	1.49%	2.11%	0.49%	2.31%
Efficiency ratio	[2]	37.67%	34.98%	38.05%	35.61%
Retail Bank
Net interest income (expense)		$ 120	$ 146	$ 245	$ 292
Provision for credit losses		5	1	8	(3)
Noninterest income		24	33	52	64
Noninterest expenses		155	147	304	292
(Benefit) provision for income taxes		(4)	7	(4)	16
Net income		(12)	24	(11)	51
Net credit-related charge-offs (recoveries)		1	0	2	0
Assets, average		3,306	2,839	3,085	2,826
Loans, average		2,479	2,107	2,277	2,105
Deposits, average		$ 22,647	$ 20,649	$ 21,921	$ 20,560
Return on average assets	[1]	(0.21%)	0.44%	(0.10%)	0.49%
Efficiency ratio	[2]	107.15%	82.26%	101.41%	81.80%
Wealth Management
Net interest income (expense)		$ 40	$ 46	$ 81	$ 93
Provision for credit losses		16	(5)	28	(10)
Noninterest income		66	68	136	132
Noninterest expenses		73	67	145	139
(Benefit) provision for income taxes		3	13	9	23
Net income		14	39	35	73
Net credit-related charge-offs (recoveries)		1	(2)	1	(3)
Assets, average		5,191	5,071	5,134	5,121
Loans, average		5,077	4,930	5,007	4,983
Deposits, average		$ 4,217	$ 3,740	$ 4,120	$ 3,770
Return on average assets	[1]	1.00%	3.10%	1.34%	2.88%
Efficiency ratio	[2]	69.86%	58.99%	67.00%	61.67%
Finance
Net interest income (expense)		$ (95)	$ (23)	$ (139)	$ (37)
Provision for credit losses		0	0	0	0
Noninterest income		11	13	25	17
Noninterest expenses		1	0	1	1
(Benefit) provision for income taxes		(20)	(4)	(28)	(8)
Net income		(65)	(6)	(87)	(13)
Net credit-related charge-offs (recoveries)		0	0	0	0
Assets, average		14,500	13,907	14,393	13,747
Loans, average		0	0	0	0
Deposits, average		950	2,174	1,043	1,655
Other
Net interest income (expense)		4	14	15	29
Provision for credit losses		0	(4)	0	(2)
Noninterest income		2	0	0	3
Noninterest expenses		4	15	14	32
(Benefit) provision for income taxes		1	0	2	(12)
Net income		1	3	(1)	14
Net credit-related charge-offs (recoveries)		0	0	0	0
Assets, average		11,255	4,114	9,019	4,202
Loans, average		28	(6)	14	(6)
Deposits, average		$ 150	$ 181	$ 166	$ 157

[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.