Derivative Instruments and Hedging Activities - Interest Rate Swap Agreements And Fair Value Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets		Other Assets
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities		Other Liabilities
Not Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Derivative Assets	$ 5,520		$ 6,208
Derivative Liabilities	5,520		6,208
Notional amount	104,897		123,197
Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Notional amount		$ 125,000
Designated as Hedging Instrument | Fair Value Swap
Derivative [Line Items]
Derivative Assets	0		0
Derivative Liabilities	2,263		5,678
Notional amount	$ 300,000		$ 300,000