Loans and Leases - Loan Modifications (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 26	$ 46
Mortgage Loans: \| Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 8	$ 0
Percent of Total Loan class	0.08%	0.00%
Mortgage Loans: \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 2	$ 44
Percent of Total Loan class	0.02%	0.42%
Mortgage Loans: \| One-to-four family first mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 2	$ 2
Percent of Total Loan class	0.03%	0.03%
Other Loans: \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 1	$ 0
Percent of Total Loan class	0.06%	0.00%
Other Loans: \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 13	$ 0
Percent of Total Loan class	0.06%	0.00%
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 10	$ 44
Interest Rate Reduction \| Mortgage Loans: \| Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 8	$ 0
Interest Rate Reduction \| Mortgage Loans: \| Multi-family \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	8.13%	0.00%
Interest Rate Reduction \| Mortgage Loans: \| Multi-family \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	6.95%	0.00%
Interest Rate Reduction \| Mortgage Loans: \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 2	$ 44
Interest Rate Reduction \| Mortgage Loans: \| Commercial real estate \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	8.08%	10.50%
Interest Rate Reduction \| Mortgage Loans: \| Commercial real estate \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	6.00%	4.00%
Interest Rate Reduction \| Mortgage Loans: \| One-to-four family first mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 0	$ 0
Weighted-average Term (in years)	15 years 3 months 18 days	12 years 8 months 12 days
Interest Rate Reduction \| Mortgage Loans: \| One-to-four family first mortgage \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	4.66%	4.84%
Interest Rate Reduction \| Mortgage Loans: \| One-to-four family first mortgage \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	3.76%	3.97%
Interest Rate Reduction \| Mortgage Loans: \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average Term (in years)	3 months 18 days
Interest Rate Reduction \| Mortgage Loans: \| Commercial and industrial \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	6.78%	0.00%
Interest Rate Reduction \| Mortgage Loans: \| Commercial and industrial \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	6.50%	0.00%
Interest Rate Reduction \| Mortgage Loans: \| Other Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average Term (in years)	1 year 9 months 18 days
Interest Rate Reduction \| Mortgage Loans: \| Other Consumer \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	11.01%	0.00%
Interest Rate Reduction \| Mortgage Loans: \| Other Consumer \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-average contractual interest rate	4.76%	0.00%
Interest Rate Reduction \| Other Loans: \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 0	$ 0
Interest Rate Reduction \| Other Loans: \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	14	1
Term Extension \| Mortgage Loans: \| Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Term Extension \| Mortgage Loans: \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Term Extension \| Mortgage Loans: \| One-to-four family first mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	1	1
Term Extension \| Other Loans: \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Term Extension \| Other Loans: \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	13	0
Combination - Interest Rate Reduction & Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	2	1
Combination - Interest Rate Reduction & Term Extension \| Mortgage Loans: \| Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Combination - Interest Rate Reduction & Term Extension \| Mortgage Loans: \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	0	0
Combination - Interest Rate Reduction & Term Extension \| Mortgage Loans: \| One-to-four family first mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	1	1
Combination - Interest Rate Reduction & Term Extension \| Other Loans: \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	1	0
Combination - Interest Rate Reduction & Term Extension \| Other Loans: \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost	$ 0	$ 0

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

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- Definition

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+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

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+ References

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