Fair Value of Financial Instruments - Estimated Fair Values (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Investment securities available for sale, at fair value	$ 6,393	$ 8,628
Investment securities held to maturity	379,592	371,305
Carrying Amount
Assets
Cash and cash equivalents	95,746	44,806
Investment securities available for sale, at fair value	6,393	8,628
Investment securities held to maturity	360,551	363,883
Loans held for sale	681	470
Loans receivable, net	1,561,586	1,584,784
FHLB stock	8,744	8,723
FRB stock	3,134	3,128
Accrued interest receivable	5,465	5,409
Interest rate contracts	34	5
Liabilities
Deposits	1,657,031	1,631,933
Advances from the Federal Home Loan Bank	156,000	156,000
Securities sold under agreements to repurchase	10,000	10,000
Accrued interest payable	207	397
Interest rate contracts	34	5
Estimated Fair Value
Assets
Cash and cash equivalents	95,746	44,806
Investment securities available for sale, at fair value	6,393	8,628
Investment securities held to maturity	379,592	371,305
Loans held for sale	703	480
Loans receivable, net	1,667,989	1,627,903
FHLB stock	8,744	8,723
FRB stock	3,134	3,128
Accrued interest receivable	5,465	5,409
Interest rate contracts	34	5
Liabilities
Deposits	1,662,674	1,632,741
Advances from the Federal Home Loan Bank	160,257	156,906
Securities sold under agreements to repurchase	10,349	9,968
Accrued interest payable	207	397
Interest rate contracts	34	5
Estimated Fair Value \| Level 1
Assets
Cash and cash equivalents	95,746	44,806
Accrued interest receivable	16	32
Estimated Fair Value \| Level 2
Assets
Investment securities available for sale, at fair value	6,393	8,628
Investment securities held to maturity	379,592	371,305
Loans held for sale	703	480
FHLB stock	8,744	8,723
FRB stock	3,134	3,128
Accrued interest receivable	984	952
Interest rate contracts	34	5
Liabilities
Deposits	1,168,792	1,167,990
Advances from the Federal Home Loan Bank	160,257	156,906
Securities sold under agreements to repurchase	10,349	9,968
Accrued interest payable	43	47
Interest rate contracts	34	5
Estimated Fair Value \| Level 3
Assets
Loans receivable, net	1,667,989	1,627,903
Accrued interest receivable	4,465	4,425
Liabilities
Deposits	493,882	464,751
Accrued interest payable	$ 164	$ 350

Fair value portion of interest payable.

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Fair value portion of interest earned but not received.

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No definition available.

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Represents the fair value portion of investments in Federal Reserve bank (FRB) stock.

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No definition available.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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