Allowance for Credit Losses on Loans and Leases - Schedule of Activity in the Allowance for Loan and Lease Losses (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	$ 1,201	$ 992	$ 393
Adjustment for Purchased PCD Loans			13
Charge-offs	(449)	(938)	(223)
Recoveries	98	46	15
Provision for (recovery of) credit losses on loans and leases	180	1,101	794
Balance, end of period	1,030	1,201	992
Loans held for investment \| Multi-family
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	639	307	178
Adjustment for Purchased PCD Loans			0
Charge-offs	(285)	(308)	(119)
Recoveries	50	5	0
Provision for (recovery of) credit losses on loans and leases	145	635	248
Balance, end of period	549	639	307
Loans held for investment \| Commercial real estate
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	304	402	67
Adjustment for Purchased PCD Loans			0
Charge-offs	(41)	(466)	(56)
Recoveries	8	8	0
Provision for (recovery of) credit losses on loans and leases	(42)	360	391
Balance, end of period	229	304	402
Loans held for investment \| One-to-four family first mortgage
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	39	47	46
Adjustment for Purchased PCD Loans			0
Charge-offs	(4)	(8)	(4)
Recoveries	0	5	0
Provision for (recovery of) credit losses on loans and leases	0	(5)	5
Balance, end of period	35	39	47
Loans held for investment \| Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	150	131	38
Adjustment for Purchased PCD Loans			13
Charge-offs	(87)	(136)	(30)
Recoveries	28	21	10
Provision for (recovery of) credit losses on loans and leases	59	134	100
Balance, end of period	150	150	131
Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	69	105	64
Adjustment for Purchased PCD Loans			0
Charge-offs	(32)	(20)	(14)
Recoveries	12	7	5
Provision for (recovery of) credit losses on loans and leases	18	(23)	50
Balance, end of period	67	$ 69	$ 105
Commercial and industrial \| Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Charge-offs	$ (87)

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
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-Name Accounting Standards Codification
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-Paragraph 1
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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