Commitments and Contingent Liabilities - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Commitments And Contingencies Liabilities [Line Items]
Rental expenses	$ 1,700,000	$ 1,300,000
Sublease income	182,000	$ 181,000
Minimum rental to be received in future on subleases	$ 1,100,000
Sublease contract maturity year	2025
Fixed rate loan commitments maturity year	2045
Variable rate loan commitments maturity year	2048
Maximum
Commitments And Contingencies Liabilities [Line Items]
Commitments to make loans period	90 days
Loan commitments fixed interest rate	18.00%
Loan commitments variable interest rate	10.00%
Minimum
Commitments And Contingencies Liabilities [Line Items]
Loan commitments fixed interest rate	2.50%
Loan commitments variable interest rate	1.25%