Disclosures About Fair Value of Financial Instruments - Summary of Estimated Fair Values and Related Carrying amounts of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financial Assets
Loans held for sale	$ 193,122	$ 55,646
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial Assets
Cash and short-term investments	77,596	60,026
Federal funds sold		480
Financial Liabilities
Federal funds purchased	135
Significant Observable Inputs (Level 2) [Member]
Financial Assets
Investment securities	123,330	129,359
Loans held for sale	193,122	55,646
Accrued interest receivable	5,193	2,590
Bank-owned life insurance	15,013	14,734
Financial Liabilities
Deposits	643,704	542,805
Other borrowed funds	459,476	124,971
Accrued interest payable	644	706
Significant Unobservable Inputs (Level 3) [Member]
Financial Assets
Net loans held for investment	1,034,898	643,878
Financial Liabilities
Deposits	278,584	168,736
Subordinated debt, net	25,326	9,784
Carrying Amount
Financial Assets
Cash and short-term investments	77,596	60,026
Federal funds sold		480
Investment securities	123,330	128,897
Loans held for sale	193,122	55,646
Net loans held for investment	1,039,180	642,262
Accrued interest receivable	5,193	2,590
Bank-owned life insurance	15,013	14,734
Financial Liabilities
Deposits	915,266	722,030
Federal funds purchased	135
Other borrowed funds	459,476	124,800
Subordinated debt, net	24,489	9,800
Accrued interest payable	644	706
Fair Value
Financial Assets
Cash and short-term investments	77,596	60,026
Federal funds sold		480
Investment securities	123,330	129,359
Loans held for sale	193,122	55,646
Net loans held for investment	1,034,898	643,878
Accrued interest receivable	5,193	2,590
Bank-owned life insurance	15,013	14,734
Financial Liabilities
Deposits	922,288	711,541
Federal funds purchased	135
Other borrowed funds	459,476	124,971
Subordinated debt, net	25,326	9,784
Accrued interest payable	$ 644	$ 706

Accrued interest receivable fair value disclosure.

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Bank owned life insurance fair value disclosure.

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Federal funds sold fair value disclosure.

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Loans held to maturity fair value disclosure.

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Fair value portion of accrued expenses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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 of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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-Publisher FASB
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-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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Fair value portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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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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