Loans Receivable and Allowance for Loan Losses - Additional Information (Details)	3 Months Ended	6 Months Ended	12 Months Ended	24 Months Ended
	Jun. 30, 2022 USD ($) Loan	Jun. 30, 2022 USD ($) Loan	Dec. 31, 2021 USD ($) Loan	Jun. 30, 2022 USD ($) Loan	Jun. 30, 2021 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Restructured loans | Loan		0	0
Number of troubled debt restructured loans | Loan	25	25	30	25
Troubled debt restructured loans	$ 7,100,000	$ 7,100,000	$ 8,700,000	$ 7,100,000
Troubled debt restructured loan, accrual status	5,000,000.0	5,000,000.0	6,200,000	5,000,000.0
Impairment reserves	223,000	223,000	243,000	223,000	$ 427,000
Loans before net deferred loan origination cost and allowance for losses on loan	1,339,409,000	1,339,409,000	1,322,098,000	1,339,409,000
Loans receivable, allowance for loan losses	17,535,000	17,535,000	16,352,000	17,535,000
Loans receivable, net	1,324,320,000	1,324,320,000	$ 1,305,078,000	1,324,320,000
Grain write-off and write-down	1,500,000	9,574,000
Grain Technologies LLC
Accounts Notes And Loans Receivable [Line Items]
Micro loan credit limit	1,000	1,000		1,000
Number of micro loan outstanding | Loan			59,180
Number of micro loan aggregate value			$ 33,900,000
Loans receivable, net	3,000,000.0	3,000,000.0		3,000,000.0
Loans receivable written-off		9,600,000
Cash received through application of security deposits		6,000,000.0
Grant received used to defray loans receivable		1,800,000
Aggregate exposure to Grain	30,900,000	30,900,000		30,900,000
Equity investment in Grain	1,000,000.0	1,000,000.0		1,000,000.0
Grain write-off and write-down	1,500,000	$ 9,600,000
Grain Technologies LLC | Microloans
Accounts Notes And Loans Receivable [Line Items]
Number of micro loan outstanding | Loan		43,073
Loans before net deferred loan origination cost and allowance for losses on loan	28,300,000	$ 28,300,000		28,300,000
Loans receivable, allowance for loan losses	1,400,000	1,400,000		1,400,000
Loans receivable, net	$ 26,900,000	$ 26,900,000		$ 26,900,000
Number of loans deemed to be fraudulent | Loan				29,592
Loans deemed fraudulent written-off				$ 20,400,000
Mortgage World Bankers Inc
Accounts Notes And Loans Receivable [Line Items]
Number of loan held for sale | Loan	17	17	27	17
Loans held for sale	$ 9,200,000	$ 9,200,000	$ 15,500,000	$ 9,200,000
Troubled Debt Restructured Loans
Accounts Notes And Loans Receivable [Line Items]
Impairment reserves	$ 223,000	$ 223,000	$ 243,000	$ 223,000
Minimum
Accounts Notes And Loans Receivable [Line Items]
Strong Pass Loans to new or existing borrowers collateralized percentage	90.00%	90.00%		90.00%