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Securities - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2025 USD ($) Segment Security	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) Security
Schedule Of Held To Maturity Securities [Line Items]
Number of Investment Securities Segments | Segment	2
Credit losses	$ 0
Municipal securities percentage of securities portfolio	0.80%
Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions Greater Than or Equal to One Year | Security	912		949
Gain (loss) on sale of investment securities	$ 0	$ 298,000
Available for Sale Securities, Amortized Cost Basis	337,219,000		$ 339,016,000
Debt Securities, Available-for-Sale	335,845,000		336,960,000
Collateralized Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	8,330,000,000		10,260,000,000
Debt Securities, Available-for-Sale	$ 7,380,000,000		$ 8,910,000,000
Securities Concentration Risk [Member] | Stockholders' Equity, Total [Member] | Other Than U.S. Government and Agencies [Member]
Schedule Of Held To Maturity Securities [Line Items]
Concentration Risk, Percentage	10.00%		10.00%

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