Fair Value of Financial Instruments - Estimated Fair Values and Related Carrying or Notional Amounts (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financial Assets:
Securities - available-for-sale	$ 204,415	$ 168,447
Reported Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	123,278	38,365
Interest-bearing time deposits	4,509	4,019
Securities - available-for-sale	204,415	168,447
Other securities	5,789	3,679
Loans held for sale	1,909	495
Loans, net	1,084,448	839,599
Interest receivable	6,862	4,542
Financial Liabilities:
Total Deposits	1,242,347	928,790
Federal funds purchased and securities sold under agreement to repurchase	27,102	32,181
Federal Home Loan Bank advances	24,532
Interest payable	750	418
Fair Value [Member]
Financial Assets:
Cash and cash equivalents	123,278	38,365
Interest-bearing time deposits	4,509	3,954
Securities - available-for-sale	204,415	168,447
Other securities	5,789	3,679
Loans held for sale	1,909	495
Loans, net	1,064,236	823,914
Interest receivable	6,832	4,542
Financial Liabilities:
Total Deposits	1,243,109	928,922
Federal funds purchased and securities sold under agreement to repurchase	27,102	3,181
Federal Home Loan Bank advances	24,393
Interest payable	750	418
Interest Bearing Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	723,684	525,955
Interest Bearing Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	723,738	525,955
Non Interest Bearing Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	242,510	215,422
Non Interest Bearing Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	242,510	215,422
Time Deposits [Member] \| Reported Value Measurement [Member]
Financial Liabilities:
Total Deposits	276,153	187,413
Time Deposits [Member] \| Fair Value [Member]
Financial Liabilities:
Total Deposits	276,861	187,545
Level 1 [Member]
Financial Assets:
Cash and cash equivalents	123,278	38,365
Securities - available-for-sale	24,795	36,935
Level 2 [Member]
Financial Assets:
Interest-bearing time deposits	4,509	3,954
Securities - available-for-sale	178,115	130,085
Financial Liabilities:
Total Deposits	242,510	215,422
Level 2 [Member] \| Non Interest Bearing Deposits [Member]
Financial Liabilities:
Total Deposits	242,510	215,422
Level 3 [Member]
Financial Assets:
Securities - available-for-sale	1,505	1,427
Other securities	5,789	3,679
Loans held for sale	1,909	495
Loans, net	1,064,236	823,914
Interest receivable	6,862	4,542
Financial Liabilities:
Total Deposits	1,000,599	713,500
Federal funds purchased and securities sold under agreement to repurchase	27,102	32,181
Federal Home Loan Bank advances	24,393
Interest payable	750	418
Level 3 [Member] \| Interest Bearing Deposits [Member]
Financial Liabilities:
Total Deposits	723,738	525,955
Level 3 [Member] \| Time Deposits [Member]
Financial Liabilities:
Total Deposits	$ 276,861	$ 187,545

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Interest bearing time deposits fair value disclosure.

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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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