Fair Value of Financial Instruments - Estimated Fair Values and Related Carrying or Notional Amounts (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial Assets:
Securities - available-for-sale	$ 204,121	$ 222,293
Reported Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	90,837	51,296
Interest-bearing time deposits	4,869	4,309
Securities - available-for-sale	204,121	222,293
Other securities	5,810	5,810
Loans held for sale	2,153	4,248
Loans, net	1,239,108	1,211,771
Interest receivable	7,114	6,769
Financial Liabilities:
Total Deposits	1,348,707	1,288,347
Federal funds purchased and securities sold under agreement to repurchase	30,585	48,073
Federal Home Loan Bank advances	24,788	24,806
Interest payable	727	754
Fair Value [Member]
Financial Assets:
Cash and cash equivalents	90,837	51,296
Interest-bearing time deposits	4,834	4,331
Securities - available-for-sale	204,121	222,293
Other securities	5,810	5,810
Loans held for sale	2,153	4,248
Loans, net	1,216,038	1,188,014
Interest receivable	7,114	6,769
Financial Liabilities:
Total Deposits	1,351,455	1,288,855
Federal funds purchased and securities sold under agreement to repurchase	30,585	48,073
Federal Home Loan Bank advances	24,858	24,811
Interest payable	727	754
Interest Bearing Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	804,990	746,628
Interest Bearing Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	805,033	746,691
Non Interest Bearing Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	261,786	265,156
Non Interest Bearing Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	261,786	265,156
Time Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	281,931	276,563
Time Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	284,636	277,008
Level 1 [Member]
Financial Assets:
Cash and cash equivalents	90,837	51,296
Securities - available-for-sale	10,073	10,021
Level 2 [Member]
Financial Assets:
Interest-bearing time deposits	4,834	4,331
Securities - available-for-sale	192,511	210,782
Financial Liabilities:
Total Deposits	261,786	265,156
Level 2 [Member] \| Non Interest Bearing Deposits [Member]
Financial Liabilities:
Total Deposits	261,786	265,156
Level 3 [Member]
Financial Assets:
Securities - available-for-sale	1,537	1,490
Other securities	5,810	5,810
Loans held for sale	2,153	4,248
Loans, net	1,216,038	1,188,014
Interest receivable	7,114	6,769
Financial Liabilities:
Total Deposits	1,089,669	1,023,699
Federal funds purchased and securities sold under agreement to repurchase	30,585	48,073
Federal Home Loan Bank advances	24,858	24,811
Interest payable	727	754
Level 3 [Member] \| Interest Bearing Deposits [Member]
Financial Liabilities:
Total Deposits	805,033	746,691
Level 3 [Member] \| Time Deposits [Member]
Financial Liabilities:
Total Deposits	$ 284,636	$ 277,008

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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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