Loans and Leases - Quality of Loans Held for Investment (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	$ 84,619	$ 69,001
Non- Accrual Loans	428	141
Loans held for investment	83,627	68,608
Officers And Directors
Financing Receivable, Recorded Investment, Past Due
Loans held for investment	9	101
Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	250	70
Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	678	211
Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	83,941	68,790
Multi-family | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	207
Other
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	27,911	14,528
Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	56,708	54,473
Mortgage Loans | Multi-family
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	37,265	38,130
Non- Accrual Loans	138	13
Mortgage Loans | Multi-family | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	121	34
Mortgage Loans | Multi-family | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	259	47
Mortgage Loans | Multi-family | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	37,006	38,083
Mortgage Loans | Commercial real estate
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	10,470	8,526
Non- Accrual Loans	128	20
Mortgage Loans | Commercial real estate | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	28	2
Mortgage Loans | Commercial real estate | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	156	22
Mortgage Loans | Commercial real estate | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	10,314	8,504
Mortgage Loans | One-to-four family first mortgage
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	6,061	5,821
Non- Accrual Loans	95	92
Mortgage Loans | One-to-four family first mortgage | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	40	21
Mortgage Loans | One-to-four family first mortgage | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	135	113
Mortgage Loans | One-to-four family first mortgage | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	5,926	5,708
Mortgage Loans | Acquisition, development, and construction
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	2,912	1,996
Non- Accrual Loans	2	0
Mortgage Loans | Acquisition, development, and construction | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	2	0
Mortgage Loans | Acquisition, development, and construction | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	4	0
Mortgage Loans | Acquisition, development, and construction | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	2,908	1,996
Other Loans:
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	27,911	14,528
Other Loans: | Commercial and industrial loans and lease financing
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	25,254	12,276
Non- Accrual Loans	43	3
Other Loans: | Commercial and industrial loans and lease financing | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	37	2
Other Loans: | Commercial and industrial loans and lease financing | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	80	5
Other Loans: | Commercial and industrial loans and lease financing | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	25,174	12,271
Other Loans: | Other
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	2,657	2,252
Non- Accrual Loans	22	13
Other Loans: | Other | Loans 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	22	11
Other Loans: | Other | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	44	24
Other Loans: | Other | Current
Financing Receivable, Recorded Investment, Past Due
Loans and leases held for investment, net of deferred loan fees and costs	$ 2,613	$ 2,228