Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary Of Significant Accounting Policies [Line Items]
Lessee, operating lease, existence of option to extend	true
Statutory federal tax rate	21.00%	21.00%	35.00%
Tax cuts and jobs act of 2017, one-time non-cash write-down of net deferred tax assets			$ 3,900,000
Defined benefit pension highest consecutive plan period			5 years	3 years
Defined benefit pension plan employees final service period			10 years
Defined contribution plan, employer matching contribution, percent				10.00%
Compensation cost	$ 0
Profit Sharing Plan
Summary Of Significant Accounting Policies [Line Items]
Defined contribution plan, maximum employee contribution, percent		100.00%
Defined contribution plan, employer matching contribution, percent		4.00%	3.00%
Defined contribution plan, minimum number of hours of service per year required for eligibility		1000 hours
Defined contribution plan, minimum service period required for eligibility		12 months
Normal retirement age of employees		65 years
Commercial Mortgage
Summary Of Significant Accounting Policies [Line Items]
Percentage of loan to value ratio	75.00%
Minimum | Residential Mortgage and Home Equity Loans
Summary Of Significant Accounting Policies [Line Items]
Percentage of loan to value ratio	80.00%
Maximum
Summary Of Significant Accounting Policies [Line Items]
Percentage of bank-owned life insurance	25.00%
Maximum | Profit Sharing Plan
Summary Of Significant Accounting Policies [Line Items]
Defined discretionary contribution plan, employer matching contribution, percent	4.00%
Maximum | Residential Mortgage and Home Equity Loans
Summary Of Significant Accounting Policies [Line Items]
Percentage of loan to value ratio	97.00%