Segment Reporting (Segment Reporting Table) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Net interest income	$ 2,511	$ 2,475
Noninterest income	2,006	1,811
Total revenue	4,517	4,286
Provision for credit losses	914	189
Depreciation and amortization	240	234
Other noninterest expense	2,303	2,344
Income before income taxes and noncontrolling interests	1,060	1,519
Income taxes (benefit)	145	248
Net income	915	1,271
Average Assets	412,436	385,898
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	1,456	1,349
Noninterest income	788	595
Total revenue	2,244	1,944
Provision for credit losses	445	128
Depreciation and amortization	57	51
Other noninterest expense	1,479	1,417
Income before income taxes and noncontrolling interests	263	348
Income taxes (benefit)	62	84
Net income	201	264
Average Assets	97,062	91,255
Corporate & Institutional Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	950	877
Noninterest income	694	576
Total revenue	1,644	1,453
Provision for credit losses	458	71
Depreciation and amortization	48	50
Other noninterest expense	674	636
Income before income taxes and noncontrolling interests	464	696
Income taxes (benefit)	94	144
Net income	370	552
Average Assets	172,502	157,169
Asset Management Group [Member]
Segment Reporting Information [Line Items]
Net interest income	88	70
Noninterest income	204	217
Total revenue	292	287
Provision for credit losses	3	(1)
Depreciation and amortization	11	12
Other noninterest expense	208	218
Income before income taxes and noncontrolling interests	70	58
Income taxes (benefit)	16	13
Net income	54	45
Average Assets	7,801	7,259
BlackRock [Member]
Segment Reporting Information [Line Items]
Noninterest income	180	233
Total revenue	180	233
Income before income taxes and noncontrolling interests	180	233
Income taxes (benefit)	23	36
Net income	157	197
Average Assets	8,511	8,080
Other [Member]
Segment Reporting Information [Line Items]
Net interest income	17	179
Noninterest income	140	190
Total revenue	157	369
Provision for credit losses	8	(9)
Depreciation and amortization	124	121
Other noninterest expense	(58)	73
Income before income taxes and noncontrolling interests	83	184
Income taxes (benefit)	(50)	(29)
Net income	133	213
Average Assets	$ 126,560	$ 122,135