Loans and Leases - Quality of Loans Held for Investment (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	$ 68,272	$ 84,619
Non- Accrual Loans	2,615	428
Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	965	250
Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	64,692	83,941
Loans held for investment | Multi-family
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	34,093	37,265
Non- Accrual Loans	1,755	138
Loans held for investment | Multi-family | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	749	121
Loans held for investment | Multi-family | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	31,589	37,006
Loans held for investment | Commercial real estate
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	8,685	10,470
Non- Accrual Loans	546	128
Loans held for investment | Commercial real estate | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	65	28
Loans held for investment | Commercial real estate | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	8,074	10,314
Loans held for investment | One-to-four family first mortgage
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	5,201	6,061
Non- Accrual Loans	70	95
Loans held for investment | One-to-four family first mortgage | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	25	40
Loans held for investment | One-to-four family first mortgage | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	5,106	5,926
Loans held for investment | Acquisition, development, and construction
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	3,151	2,912
Non- Accrual Loans	18	2
Loans held for investment | Acquisition, development, and construction | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	5	2
Loans held for investment | Acquisition, development, and construction | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	3,128	2,908
Other loans held for investment | Commercial and industrial loans and lease financing
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	15,376	25,254
Non- Accrual Loans	202	43
Other loans held for investment | Commercial and industrial loans and lease financing | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	110	37
Other loans held for investment | Commercial and industrial loans and lease financing | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	15,064	25,174
Other loans held for investment | Other
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	1,766	2,657
Non- Accrual Loans	24	22
Other loans held for investment | Other | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	11	22
Other loans held for investment | Other | Current
Financing Receivable, Recorded Investment, Past Due
Total Loans Receivable	$ 1,731	$ 2,613