Loans and Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest	$ 134	$ 180
Net loans and leases	54,189	57,269
Loans and leases	54,859	58,232
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged to secure potential borrowings	6,900	7,800
Loans and leases	$ 31,068	33,104
Commercial \| Minimum \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan grades	1
Commercial \| Maximum \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan grades	16
Commercial \| C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 31,068	33,104
Commercial \| C&I \| Loans to mortgage companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 4,518	5,404
Percentage contributed	26.00%
Commercial \| C&I \| Finance And Insurance Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 3,500
Commercial \| Loans to mortgage companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,518	5,404
Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net loans and leases	$ 36,600	$ 38,600

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Amount, before allowance for credit loss, of accrued interest on financing receivable.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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