Borrowings Information related to Trust Preferred Securites (Details) - Junior Subordinated Debt [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Capital Trust V Preferred Securites Due 2037
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Face Amount	$ 50,000
Capital Trust V Preferred Securites Due 2037 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.48%
Debt Instrument, Interest Rate, Stated Percentage	7.15%
Central Bancorp Capital Trust I Securities Due in 2034
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Face Amount	$ 5,100
Central Bancorp Capital Trust I Securities Due in 2034 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.44%
Debt Instrument, Interest Rate, Stated Percentage	8.11%
Central Bancorp Capital Trust II Securities Due in 2037
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Face Amount	$ 5,900
Central Bancorp Capital Trust II Securities Due in 2037 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Information related to Trust Preferred Securites [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.65%
Debt Instrument, Interest Rate, Stated Percentage	7.32%