Loans and Leases - Performance of Loans Modified in Last 12 Months (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Modified [Line Items]
Total	$ 34	$ 27
Current
Financing Receivable, Modified [Line Items]
Total	18	8
Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total	0	10
90+ Past Due
Financing Receivable, Modified [Line Items]
Total	16	9
Loans held for investment | Multi-family
Financing Receivable, Modified [Line Items]
Total	2
Loans held for investment | Multi-family | Current
Financing Receivable, Modified [Line Items]
Total	2
Loans held for investment | Multi-family | Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total	0
Loans held for investment | Multi-family | 90+ Past Due
Financing Receivable, Modified [Line Items]
Total	0
Loans held for investment | Commercial real estate
Financing Receivable, Modified [Line Items]
Total	12	1
Loans held for investment | Commercial real estate | Current
Financing Receivable, Modified [Line Items]
Total	8	1
Loans held for investment | Commercial real estate | Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total	0	0
Loans held for investment | Commercial real estate | 90+ Past Due
Financing Receivable, Modified [Line Items]
Total	4	0
Loans held for investment | One-to-four family first mortgage
Financing Receivable, Modified [Line Items]
Total	16	11
Loans held for investment | One-to-four family first mortgage | Current
Financing Receivable, Modified [Line Items]
Total	8	3
Loans held for investment | One-to-four family first mortgage | Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total	0	0
Loans held for investment | One-to-four family first mortgage | 90+ Past Due
Financing Receivable, Modified [Line Items]
Total	8	8
Other loans held for investment | Commercial and industrial
Financing Receivable, Modified [Line Items]
Total	4	13
Other loans held for investment | Commercial and industrial | Current
Financing Receivable, Modified [Line Items]
Total	0	3
Other loans held for investment | Commercial and industrial | Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total	0	9
Other loans held for investment | Commercial and industrial | 90+ Past Due
Financing Receivable, Modified [Line Items]
Total	$ 4	1
Other loans held for investment | Other Consumer
Financing Receivable, Modified [Line Items]
Total		2
Other loans held for investment | Other Consumer | Current
Financing Receivable, Modified [Line Items]
Total		1
Other loans held for investment | Other Consumer | Loans 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Total		1
Other loans held for investment | Other Consumer | 90+ Past Due
Financing Receivable, Modified [Line Items]
Total		$ 0