Operating Segments (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		$ 3,587	$ 3,527	$ 7,094	$ 6,899
Allocated provision for credit losses		488	451	946	951
Noninterest Income		1,400	(5,212)	2,792	(3,766)
Personnel expense		1,653	1,661	3,240	3,291
Amortization of intangibles		73	89	148	177
Restructuring Charges		28	33	66	84
Other expenses		2,986	3,094	5,892	6,047
Income (loss) before income taxes		1,513	(5,230)	3,048	(3,865)
Provision (benefit) for income taxes		273	(1,324)	547	(1,092)
Segment net income (loss) from continuing operations		1,240	(3,906)	2,501	(2,773)
Identifiable assets (period end) of continuing operations		543,833		543,833		$ 531,176
CSBB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		1,488	1,291	2,915	2,558
WB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		1,880	2,182	3,772	4,413
OT&C
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income	[1]	219	54	407	(72)
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		3,587	3,527	7,094	6,899
Allocated provision for credit losses		488	451	946	951
Noninterest Income		1,400	(5,212)	2,792	(3,766)
Personnel expense		1,653	1,661	3,240	3,291
Amortization of intangibles		73	89	148	177
Restructuring Charges		28	33	66	84
Other direct noninterest expense	[2]	1,232	1,311	2,438	2,495
Total direct noninterest expense		2,986	3,094	5,892	6,047
Expense allocation		0	0	0	0
Other expenses		2,986	3,094	5,892	6,047
Income (loss) before income taxes		1,513	(5,230)	3,048	(3,865)
Provision (benefit) for income taxes		273	(1,324)	547	(1,092)
Segment net income (loss) from continuing operations		1,240	(3,906)	2,501	(2,773)
Identifiable assets (period end) of continuing operations		543,833	519,853	543,833	519,853
Operating Segments | CSBB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		2,359	2,507	4,644	4,985
Allocated provision for credit losses		384	308	712	621
Noninterest Income		519	504	1,022	1,002
Personnel expense		409	417	817	822
Amortization of intangibles		39	45	78	91
Restructuring Charges		1	1	1	2
Other direct noninterest expense	[2]	281	265	556	509
Total direct noninterest expense		730	728	1,452	1,424
Expense allocation		970	934	1,911	1,824
Other expenses		1,700	1,662	3,363	3,248
Income (loss) before income taxes		794	1,041	1,591	2,118
Provision (benefit) for income taxes		193	250	387	510
Segment net income (loss) from continuing operations		601	791	1,204	1,608
Identifiable assets (period end) of continuing operations		152,221	144,217	152,221	144,217
Operating Segments | WB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		1,661	1,623	3,254	3,238
Allocated provision for credit losses		104	142	235	329
Noninterest Income		942	986	1,891	1,966
Personnel expense		559	586	1,107	1,166
Amortization of intangibles		35	41	71	83
Restructuring Charges		7	8	8	15
Other direct noninterest expense	[2]	200	186	392	362
Total direct noninterest expense		801	821	1,578	1,626
Expense allocation		526	447	1,051	975
Other expenses		1,327	1,268	2,629	2,601
Income (loss) before income taxes		1,172	1,199	2,281	2,274
Provision (benefit) for income taxes		236	239	459	448
Segment net income (loss) from continuing operations		936	960	1,822	1,826
Identifiable assets (period end) of continuing operations		214,793	207,484	214,793	207,484
Operating Segments | OT&C
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income	[1]	(433)	(603)	(804)	(1,324)
Allocated provision for credit losses	[1]	0	1	(1)	1
Noninterest Income	[1]	(61)	(6,702)	(121)	(6,734)
Personnel expense	[1]	685	658	1,316	1,303
Amortization of intangibles	[1]	(1)	3	(1)	3
Restructuring Charges	[1]	20	24	57	67
Other direct noninterest expense	[1],[2]	751	860	1,490	1,624
Total direct noninterest expense	[1]	1,455	1,545	2,862	2,997
Expense allocation	[1]	(1,496)	(1,381)	(2,962)	(2,799)
Other expenses	[1]	(41)	164	(100)	198
Income (loss) before income taxes	[1]	(453)	(7,470)	(824)	(8,257)
Provision (benefit) for income taxes	[1]	(156)	(1,813)	(299)	(2,050)
Segment net income (loss) from continuing operations	[1]	(297)	(5,657)	(525)	(6,207)
Identifiable assets (period end) of continuing operations	[1]	176,819	168,152	176,819	168,152
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		0	0	0	0
Intersegment Eliminations | CSBB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		871	1,216	1,729	2,427
Intersegment Eliminations | WB
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income		(219)	(559)	(518)	(1,175)
Intersegment Eliminations | OT&C
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Interest Income	[1]	$ (652)	$ (657)	$ (1,211)	$ (1,252)

[1] (1)As described above, includes the Company’s investment securities portfolio, most long-term debt, derivative instruments used for balance sheet hedging, short-term liquidity and funding activities, balance sheet risk management, most bank-owned real estate assets, as well as functional activities such as finance, enterprise risk, legal, and enterprise technology and management. Additionally, houses intersegment eliminations, including for residual interest rate risk, intersegment net referral fees, and expense allocations. May also include financial data from business units below the quantitative and qualitative thresholds requiring disclosure.

[2] Other direct noninterest expense within the table above includes expenses for occupancy and equipment, professional fees and outside processing, regulatory costs, and other expenses.