Derivative Instruments and Hedge Activities - Summary of Derivative Financial Instruments and Classification on Consolidated Statements of Financial Condition (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Derivatives Fair Value [Line Items]
Notional Amount	$ 739,390,000	$ 391,847,000
Other Assets	16,949,000	17,149,000
Other Liabilities	(12,380,000)	(18,133,000)
Cash Flow Hedging
Derivatives Fair Value [Line Items]
Notional Amount	350,000,000
Other Assets	4,992,000
Other Interest Rate Derivatives
Derivatives Fair Value [Line Items]
Notional Amount	381,169,000
Other Assets	11,957,000
Other Liabilities	(12,368,000)
Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedging
Derivatives Fair Value [Line Items]
Notional Amount	350,000,000	0
Other Assets	4,992,000
Derivatives Not Designated As Hedging Instruments | Other Credit Derivatives
Derivatives Fair Value [Line Items]
Notional Amount	8,221,000	8,437,000
Other Liabilities	(12,000)	(17,000)
Derivatives Not Designated As Hedging Instruments | Other Interest Rate Derivatives
Derivatives Fair Value [Line Items]
Notional Amount	381,169,000	383,410,000
Other Assets	11,957,000	17,149,000
Other Liabilities	$ (12,368,000)	$ (18,116,000)