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Concentrations of Credit Risk (Details) - USD ($) $ in Millions		12 Months Ended
	Aug. 06, 2021	Dec. 31, 2022	Dec. 31, 2021
Commercial real estate | Small Business Administration Paycheck Protection Program
Concentration Risk [Line Items]
Decrease in unsecured loans		$ 107.7
U.S. Government, its agencies and Government Sponsored Enterprises (GSEs) | Credit concentration risk | U.S. Government And Government-Sponsored Enterprises
Concentration Risk [Line Items]
Concentration risk amount		$ 1,535.0	$ 1,277.0
Concentration risk percentage		87.00%	85.00%
Non-Government Sponsored Enterprises | Credit concentration risk | U.S. Government And Government-Sponsored Enterprises
Concentration Risk [Line Items]
Concentration risk amount	$ 516.6
Non-Government Sponsored Enterprises | Credit concentration risk | Non-Government Sponsored Enterprises
Concentration Risk [Line Items]
Concentration risk percentage		1.00%	2.00%
Loans portfolio | Credit concentration risk
Concentration Risk [Line Items]
Concentration risk, threshold for major borrower, percentage		3.00%	3.00%
Loans on real estate | Credit concentration risk | Residential loans
Concentration Risk [Line Items]
Concentration risk percentage		89.00%	84.00%

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Concentration Risk, Percentage, Threshold For Major Borrower

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Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

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The increase (decrease) during the reporting period in outstanding loans including accrued interest.

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