Loans and Leases - Information Regarding Troubled Debt Restructurings (Details) - Non-Covered Loans - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	$ 29	$ 34
Accruing
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	16	15
Non-Accrual
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	13	19
Multi-Family
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	7
Multi-Family | Non-Accrual
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	7
Commercial Real Estate
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	16	15
Commercial Real Estate | Accruing
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	16	15
Commercial and Industrial
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	6	19
Commercial and Industrial | Non-Accrual
Financing Receivable Modifications [Line Items]
Troubled debt restructurings	$ 6	$ 19