Segment Reporting (Tables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income	$ 9,721	$ 9,108	$ 8,391
Noninterest Income	7,411	7,221	6,771
Total revenue	17,132	16,329	15,162
Provision for credit losses (benefit)	408	441	433
Depreciation and amortization	940	921	843
Other noninterest expense	9,356	9,477	8,633
Income before income taxes and noncontrolling interests	6,428	5,490	5,253
Income taxes (benefit)	1,082	102	1,268
Net income	5,346	5,388	3,985
Average Assets	378,235	371,769	361,260
Retail Banking
Segment Reporting Information [Line Items]
Net interest income	5,119	4,625	4,509
Noninterest Income	2,631	2,236	2,693
Total revenue	7,750	6,861	7,202
Provision for credit losses (benefit)	373	347	297
Depreciation and amortization	206	177	175
Other noninterest expense	5,772	5,569	5,347
Income before income taxes and noncontrolling interests	1,399	768	1,383
Income taxes (benefit)	335	321	510
Net income	1,064	447	873
Average Assets	89,739	88,663	85,871
Corporate & Institutional Banking
Segment Reporting Information [Line Items]
Net interest income	3,551	3,396	3,181
Noninterest Income	2,406	2,271	2,035
Total revenue	5,957	5,667	5,216
Provision for credit losses (benefit)	85	160	177
Depreciation and amortization	186	184	153
Other noninterest expense	2,520	2,370	2,174
Income before income taxes and noncontrolling interests	3,166	2,953	2,712
Income taxes (benefit)	658	520	871
Net income	2,508	2,433	1,841
Average Assets	154,119	148,414	140,309
Asset Management Group
Segment Reporting Information [Line Items]
Net interest income	287	287	300
Noninterest Income	892	881	851
Total revenue	1,179	1,168	1,151
Provision for credit losses (benefit)	2	1	(6)
Depreciation and amortization	52	50	45
Other noninterest expense	861	855	813
Income before income taxes and noncontrolling interests	264	262	299
Income taxes (benefit)	62	75	110
Net income	202	187	189
Average Assets	7,423	7,511	7,707
BlackRock
Segment Reporting Information [Line Items]
Noninterest Income	935	1,078	685
Total revenue	935	1,078	685
Income before income taxes and noncontrolling interests	935	1,078	685
Income taxes (benefit)	154	(686)	153
Net income	781	1,764	532
Average Assets	8,061	7,677	7,118
Other
Segment Reporting Information [Line Items]
Net interest income	764	800	401
Noninterest Income	547	755	507
Total revenue	1,311	1,555	908
Provision for credit losses (benefit)	(52)	(67)	(35)
Depreciation and amortization	496	510	470
Other noninterest expense	203	683	299
Income before income taxes and noncontrolling interests	664	429	174
Income taxes (benefit)	(127)	(128)	(376)
Net income	791	557	550
Average Assets	$ 118,893	$ 119,504	$ 120,255