Derivative Instruments and Hedge Activities - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative notional amount		$ 341,358,000	$ 548,969,000
Unrealized gain (loss) to be reclassified as an decrease to interest expense during the next twelve months		(85,000)
Fair value of derivatives net liability position		8,500,000
Collateral amount posted		8,500,000
Settlement obligation termination value		8,500,000
Interest Rate Swaps | Interest Expense
Derivative [Line Items]
Increase (decrease) in FHLB expense		(1,600,000)	(1,300,000)	$ 579,000
Other Interest Rate Derivatives
Derivative [Line Items]
Derivative notional amount		$ 332,056,000
Derivative maturity date, start year		Apr. 30, 2020
Derivative maturity date, end year		Jan. 31, 2030
Derivative instruments transaction fees		$ 1,200,000	1,700,000	$ 393,000
Other Credit Derivatives
Derivative [Line Items]
Derivative notional amount		9,300,000	4,400,000
Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedges
Derivative [Line Items]
Derivative notional amount		0	250,000,000
Termination of designated as cash flow hedges to reduce interest risk	$ 250,000,000
Transaction, net of tax	$ 383,000
Remaining balance in accumulated other comprehensive income		$ 366,000
Federal Home Loan Bank Advances | Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedges
Derivative [Line Items]
Derivative notional amount			$ 250,000,000