Quarterly report [Sections 13 or 15(d)]

Outstanding Loans and Leases and Allowance for Credit Losses - Residential Mortgage - Credit Quality Indicators (Details)

Outstanding Loans and Leases and Allowance for Credit Losses - Residential Mortgage - Credit Quality Indicators (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,205,035		$ 1,185,700
Total gross charge-offs	1,737	$ 1,733
Small Business Card Loans \| United States
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross charge-offs	146		555
Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross charge-offs	16	$ 6
Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	236,176		236,302
Originated in current fiscal year	6,564		24,345
Originated in fiscal year before current fiscal year	22,866		15,450
Originated two years before current fiscal year	14,443		13,099
Originated three years before current fiscal year	12,553		37,861
Originated four years before current fiscal year	37,278		72,863
Prior	142,472		72,684
Total gross charge-offs	9		24
Gross charge-offs, Originated in current fiscal year	0		0
Gross charge-offs, Originated in fiscal year before current fiscal year	1		4
Gross charge-offs, Originated two years before current fiscal year	3		6
Gross charge-offs, Originated three years before current fiscal year	1		6
Gross charge-offs, Originated four years before current fiscal year	2		2
Gross charge-offs, Prior	2		6
Consumer real estate \| Less than 620 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,121		3,076
Originated in current fiscal year	50		197
Originated in fiscal year before current fiscal year	216		242
Originated two years before current fiscal year	240		193
Originated three years before current fiscal year	188		533
Originated four years before current fiscal year	530		724
Prior	1,897		1,187
Consumer real estate \| Greater than or equal to 620 and less than 660 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,283		2,277
Originated in current fiscal year	37		192
Originated in fiscal year before current fiscal year	182		150
Originated two years before current fiscal year	137		143
Originated three years before current fiscal year	147		408
Originated four years before current fiscal year	378		540
Prior	1,402		844
Consumer real estate \| Greater than or equal to 660 and less than 740 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	24,438		25,065
Originated in current fiscal year	486		2,488
Originated in fiscal year before current fiscal year	2,419		1,854
Originated two years before current fiscal year	1,663		1,507
Originated three years before current fiscal year	1,397		4,253
Originated four years before current fiscal year	4,134		6,668
Prior	14,339		8,295
Consumer real estate \| Greater than or equal to 740 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	197,450		196,808
Originated in current fiscal year	5,987		21,311
Originated in fiscal year before current fiscal year	19,888		13,006
Originated two years before current fiscal year	12,204		11,089
Originated three years before current fiscal year	10,657		32,390
Originated four years before current fiscal year	31,964		62,041
Prior	116,750		56,971
Less than or equal to 90 percent \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	223,480		223,761
Originated in current fiscal year	6,335		22,998
Originated in fiscal year before current fiscal year	21,511		14,267
Originated two years before current fiscal year	13,236		12,431
Originated three years before current fiscal year	11,866		37,042
Originated four years before current fiscal year	36,432		69,829
Prior	134,100		67,194
Greater than 90 percent but less than or equal to 100 percent \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,371		2,318
Originated in current fiscal year	92		737
Originated in fiscal year before current fiscal year	709		644
Originated two years before current fiscal year	598		375
Originated three years before current fiscal year	372		405
Originated four years before current fiscal year	414		94
Prior	186		63
Greater than 100 percent \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,441		1,147
Originated in current fiscal year	133		453
Originated in fiscal year before current fiscal year	485		341
Originated two years before current fiscal year	410		126
Originated three years before current fiscal year	151		137
Originated four years before current fiscal year	160		50
Prior	102		40
Fully-insured loans \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	8,884		9,076
Originated in current fiscal year	4		157
Originated in fiscal year before current fiscal year	161		198
Originated two years before current fiscal year	199		167
Originated three years before current fiscal year	164		277
Originated four years before current fiscal year	272		2,890
Prior	$ 8,084		$ 5,387