Segment Reporting (Segment Reporting Table) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Net interest income	$ 2,498	$ 2,413	$ 4,973	$ 4,774
Noninterest income	1,941	1,911	3,752	3,661
Total revenue	4,439	4,324	8,725	8,435
Provision for credit losses (benefit)	180	80	369	172
Depreciation and amortization	257	237	491	470
Other noninterest expense	2,354	2,347	4,698	4,641
Income before income taxes and noncontrolling interests	1,648	1,660	3,167	3,152
Income taxes (benefit)	274	304	522	557
Net income	1,374	1,356	2,645	2,595
Average Assets	396,962	375,627	391,461	375,949
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	1,376	1,277	2,725	2,495
Noninterest income	657	678	1,252	1,313
Total revenue	2,033	1,955	3,977	3,808
Provision for credit losses (benefit)	81	72	209	141
Depreciation and amortization	59	47	110	92
Other noninterest expense	1,468	1,474	2,885	2,885
Income before income taxes and noncontrolling interests	425	362	773	690
Income taxes (benefit)	100	88	184	167
Net income	325	274	589	523
Average Assets	92,350	89,021	91,805	88,879
Corporate & Institutional Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	897	877	1,774	1,738
Noninterest income	661	635	1,237	1,182
Total revenue	1,558	1,512	3,011	2,920
Provision for credit losses (benefit)	100	15	171	56
Depreciation and amortization	50	45	100	93
Other noninterest expense	648	623	1,284	1,228
Income before income taxes and noncontrolling interests	760	829	1,456	1,543
Income taxes (benefit)	158	177	302	328
Net income	602	652	1,154	1,215
Average Assets	163,897	153,619	160,551	152,769
Asset Management Group [Member]
Segment Reporting Information [Line Items]
Net interest income	68	72	138	146
Noninterest income	286	222	503	448
Total revenue	354	294	641	594
Provision for credit losses (benefit)		7	(1)
Depreciation and amortization	28	13	40	25
Other noninterest expense	221	218	439	431
Income before income taxes and noncontrolling interests	105	56	163	138
Income taxes (benefit)	25	13	38	33
Net income	80	43	125	105
Average Assets	7,150	7,469	7,204	7,484
BlackRock [Member]
Segment Reporting Information [Line Items]
Noninterest income	224	232	457	467
Total revenue	224	232	457	467
Income before income taxes and noncontrolling interests	224	232	457	467
Income taxes (benefit)	35	37	71	75
Net income	189	195	386	392
Average Assets	8,184	7,811	8,184	7,811
Other [Member]
Segment Reporting Information [Line Items]
Net interest income	157	187	336	395
Noninterest income	113	144	303	251
Total revenue	270	331	639	646
Provision for credit losses (benefit)	(1)	(14)	(10)	(25)
Depreciation and amortization	120	132	241	260
Other noninterest expense	17	32	90	97
Income before income taxes and noncontrolling interests	134	181	318	314
Income taxes (benefit)	(44)	(11)	(73)	(46)
Net income	178	192	391	360
Average Assets	$ 125,381	$ 117,707	$ 123,717	$ 119,006