Quarterly report [Sections 13 or 15(d)]

Outstanding Loans and Leases and Allowance for Credit Losses - Home Equity - Credit Quality Indicators Including Vintage (Details)

Outstanding Loans and Leases and Allowance for Credit Losses - Home Equity - Credit Quality Indicators Including Vintage (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]
Loans and leases	$ 1,205,035		$ 1,185,700
Total gross charge-offs	1,737	$ 1,733
Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total gross charge-offs	16	$ 6
Consumer real estate \| Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	26,762		26,823
Total gross charge-offs	7		16
Consumer real estate \| Home equity \| Less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	706		701
Consumer real estate \| Home equity \| Greater than or equal to 620 and less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	588		595
Consumer real estate \| Home equity \| Greater than or equal to 660 and less than 740
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	4,990		5,036
Consumer real estate \| Home equity \| Greater than or equal to 740
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	20,478		20,491
Consumer real estate \| Home Equity Loans and Reverse Mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	681		697
Total gross charge-offs	0		0
Consumer real estate \| Home Equity Loans and Reverse Mortgages \| Less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	65		67
Consumer real estate \| Home Equity Loans and Reverse Mortgages \| Greater than or equal to 620 and less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	43		44
Consumer real estate \| Home Equity Loans and Reverse Mortgages \| Greater than or equal to 660 and less than 740
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	164		173
Consumer real estate \| Home Equity Loans and Reverse Mortgages \| Greater than or equal to 740
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	409		413
Consumer real estate \| Reverse Mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	451		457
Consumer real estate \| Home Equity Loan no Longer Originated
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	230		240
Consumer real estate \| Revolving Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	22,988		23,023
Gross charge-offs, Revolving Loans	5		10
Consumer real estate \| Revolving Loans \| Less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	408		399
Consumer real estate \| Revolving Loans \| Greater than or equal to 620 and less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	377		375
Consumer real estate \| Revolving Loans \| Greater than or equal to 660 and less than 740
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	4,042		4,057
Consumer real estate \| Revolving Loans \| Greater than or equal to 740
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	18,161		18,192
Consumer real estate \| Revolving Loans Converted to Term Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	3,093		3,103
Gross charge-offs, Revolving Loans Converted to Term Loans	2		6
Consumer real estate \| Revolving Loans Converted to Term Loans \| Less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	233		235
Consumer real estate \| Revolving Loans Converted to Term Loans \| Greater than or equal to 620 and less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	168		176
Consumer real estate \| Revolving Loans Converted to Term Loans \| Greater than or equal to 660 and less than 740
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	784		806
Consumer real estate \| Revolving Loans Converted to Term Loans \| Greater than or equal to 740
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	1,908		1,886
Less than or equal to 90 percent \| Consumer real estate \| Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	26,596		26,686
Less than or equal to 90 percent \| Consumer real estate \| Home Equity Loans and Reverse Mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	667		687
Less than or equal to 90 percent \| Consumer real estate \| Revolving Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	22,849		22,909
Less than or equal to 90 percent \| Consumer real estate \| Revolving Loans Converted to Term Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	3,080		3,090
Greater than 90 percent but less than or equal to 100 percent \| Consumer real estate \| Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	96		70
Greater than 90 percent but less than or equal to 100 percent \| Consumer real estate \| Home Equity Loans and Reverse Mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	6		3
Greater than 90 percent but less than or equal to 100 percent \| Consumer real estate \| Revolving Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	86		63
Greater than 90 percent but less than or equal to 100 percent \| Consumer real estate \| Revolving Loans Converted to Term Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	4		4
Greater than 100 percent \| Consumer real estate \| Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	70		67
Greater than 100 percent \| Consumer real estate \| Home Equity Loans and Reverse Mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	8		7
Greater than 100 percent \| Consumer real estate \| Revolving Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	53		51
Greater than 100 percent \| Consumer real estate \| Revolving Loans Converted to Term Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Converted to Term Loans	$ 9		$ 9