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		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,165,900		$ 1,165,900		$ 1,095,835
Total gross charge-offs	1,701	$ 1,800	5,258	$ 5,317
Small Business Card Loans \| United States
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross charge-offs			418		489
Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross charge-offs	9	$ 15	29	$ 34
Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	235,429		235,429		228,199
Originated in current fiscal year	16,984		16,984		19,555
Originated in fiscal year before current fiscal year	17,088		17,088		13,758
Originated two years before current fiscal year	13,918		13,918		37,665
Originated three years before current fiscal year	38,416		38,416		75,243
Originated four years before current fiscal year	74,090		74,090		35,118
Prior	74,933		74,933		46,860
Total gross charge-offs			18		21
Gross charge-offs, Originated in current fiscal year			0		2
Gross charge-offs, Originated in fiscal year before current fiscal year			1		3
Gross charge-offs, Originated two years before current fiscal year			6		6
Gross charge-offs, Originated three years before current fiscal year			5		2
Gross charge-offs, Originated four years before current fiscal year			1		1
Gross charge-offs, Prior			5		7
Consumer real estate \| Less than 620 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,914		2,914		2,619
Originated in current fiscal year	139		139		172
Originated in fiscal year before current fiscal year	225		225		171
Originated two years before current fiscal year	184		184		484
Originated three years before current fiscal year	510		510		649
Originated four years before current fiscal year	693		693		427
Prior	1,163		1,163		716
Consumer real estate \| Greater than or equal to 620 and less than 660 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,320		2,320		2,187
Originated in current fiscal year	150		150		170
Originated in fiscal year before current fiscal year	167		167		145
Originated two years before current fiscal year	136		136		396
Originated three years before current fiscal year	395		395		515
Originated four years before current fiscal year	580		580		366
Prior	892		892		595
Consumer real estate \| Greater than or equal to 660 and less than 740 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	24,849		24,849		25,166
Originated in current fiscal year	1,748		1,748		2,167
Originated in fiscal year before current fiscal year	2,014		2,014		1,745
Originated two years before current fiscal year	1,629		1,629		4,542
Originated three years before current fiscal year	4,317		4,317		7,008
Originated four years before current fiscal year	6,612		6,612		3,801
Prior	8,529		8,529		5,903
Consumer real estate \| Greater than or equal to 740 \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	196,056		196,056		188,314
Originated in current fiscal year	14,799		14,799		16,758
Originated in fiscal year before current fiscal year	14,481		14,481		11,507
Originated two years before current fiscal year	11,796		11,796		31,941
Originated three years before current fiscal year	32,912		32,912		63,918
Originated four years before current fiscal year	63,252		63,252		27,956
Prior	58,816		58,816		36,234
Less than or equal to 90 percent \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	223,071		223,071		215,575
Originated in current fiscal year	15,965		15,965		18,115
Originated in fiscal year before current fiscal year	15,885		15,885		12,910
Originated two years before current fiscal year	13,273		13,273		36,748
Originated three years before current fiscal year	37,657		37,657		71,912
Originated four years before current fiscal year	70,994		70,994		32,504
Prior	69,297		69,297		43,386
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	2,090		2,090		1,848
Originated in current fiscal year	538		538		724
Originated in fiscal year before current fiscal year	684		684		463
Originated two years before current fiscal year	362		362		471
Originated three years before current fiscal year	349		349		122
Originated four years before current fiscal year	92		92		31
Prior	65		65		37
Greater than 100 percent \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	978		978		863
Originated in current fiscal year	333		333		428
Originated in fiscal year before current fiscal year	318		318		195
Originated two years before current fiscal year	110		110		144
Originated three years before current fiscal year	128		128		56
Originated four years before current fiscal year	51		51		15
Prior	38		38		25
Fully-insured loans \| Consumer real estate \| Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	9,290		9,290		9,913
Originated in current fiscal year	148		148		288
Originated in fiscal year before current fiscal year	201		201		190
Originated two years before current fiscal year	173		173		302
Originated three years before current fiscal year	282		282		3,153
Originated four years before current fiscal year	2,953		2,953		2,568
Prior	$ 5,533		$ 5,533		$ 3,412