Allowance for Credit Losses on Loans and Leases - Schedule of Non-Accrual Loans (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	$ 1,571	$ 1,537
Non-accrual loans with an allowance recorded:	1,229	1,438
Total non-accrual loans	2,800	2,975
Related allowance:	163	222
Mortgage Loans Held for Investment \| Multi-family
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	1,143	1,141
Non-accrual loans with an allowance recorded:	989	1,120
Total non-accrual loans	2,132	2,261
Related allowance:	83	99
Mortgage Loans Held for Investment \| Commercial real estate
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	354	319
Non-accrual loans with an allowance recorded:	117	170
Total non-accrual loans	471	489
Related allowance:	30	60
Mortgage Loans Held for Investment \| One-to-four family first mortgage
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	42	40
Non-accrual loans with an allowance recorded:	18	24
Total non-accrual loans	60	64
Related allowance:	2	2
Other
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	0	0
Non-accrual loans with an allowance recorded:	26	31
Total non-accrual loans	26	31
Related allowance:	25	29
Other \| Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Non-accrual loans with no related allowance:	32	37
Non-accrual loans with an allowance recorded:	79	93
Total non-accrual loans	111	130
Related allowance:	$ 23	$ 32