Loans and Related Allowance for Credit Losses, Payment Performance of Commercial Loan Modifications (Details) - Total Commercial [Member] - USD ($)
$ in Millions

Loans and Related Allowance for Credit Losses, Payment Performance of Commercial Loan Modifications (Details) - Total Commercial [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	$ 2,975		$ 2,975
Charge-offs	5	$ 87	46	$ 102
Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	2,740		2,740
30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	50		50
90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	185		185
Excluding modifications in payment deferral period member [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		3,692		3,692
Excluding modifications in payment deferral period member [Member] \| Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		3,637		3,637
Excluding modifications in payment deferral period member [Member] \| 30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		37		37
Excluding modifications in payment deferral period member [Member] \| 90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		18		18
Commercial and industrial loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	1,202		1,202
Charge-offs	5	87	11	102
Commercial and industrial loans [Member] \| Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	1,156		1,156
Commercial and industrial loans [Member] \| 30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	10		10
Commercial and industrial loans [Member] \| 90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	36		36
Commercial and industrial loans [Member] \| Excluding modifications in payment deferral period member [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		917		917
Commercial and industrial loans [Member] \| Excluding modifications in payment deferral period member [Member] \| Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		895		895
Commercial and industrial loans [Member] \| Excluding modifications in payment deferral period member [Member] \| 30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		8		8
Commercial and industrial loans [Member] \| Excluding modifications in payment deferral period member [Member] \| 90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		14		14
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	1,773		1,773
Charge-offs	0	0	35	0
Commercial real estate [Member] \| Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	1,584		1,584
Commercial real estate [Member] \| 30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	40		40
Commercial real estate [Member] \| 90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period	$ 149		$ 149
Commercial real estate [Member] \| Excluding modifications in payment deferral period member [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		2,775		2,775
Commercial real estate [Member] \| Excluding modifications in payment deferral period member [Member] \| Current-29 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		2,742		2,742
Commercial real estate [Member] \| Excluding modifications in payment deferral period member [Member] \| 30-89 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		29		29
Commercial real estate [Member] \| Excluding modifications in payment deferral period member [Member] \| 90 days or more past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified during the period		$ 4		$ 4