Loan Portfolio (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 116,191	$ 101,854
Accrued interest	274	198
Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	79,597	70,836
Accrued interest	197	113
Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	36,594	31,018
Accrued interest	77	85
Commercial and Industrial | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	56,971	50,525
Commercial mortgage | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	16,400	14,244
Construction | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,349	1,996
Total commercial real estate loans | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	18,749	16,240
Commercial lease financing | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,877	4,071
Real estate — residential mortgage | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	20,838	15,756
Home equity loans | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,926	8,467
Total residential — prime loans | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	28,764	24,223
Consumer direct loans | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	6,803	5,753
Credit cards | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	977	972
Consumer indirect loans | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	50	70
Credit cards | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	166	139
Credit cards | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	977	972
Collateral pledged | Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10	16
Education Lending | Discontinued operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 467	$ 567