Other Borrowed Funds - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Other borrowings	$ 459,476	$ 124,800
Federal Reserve Paycheck Protection Program Liquidity [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Other borrowings	$ 344,500
Interest rate	0.35%
Federal Home Loan Bank of Atlanta [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank advance	$ 115,000	$ 124,800
Decrease in other borrowings	$ (9,800)

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ 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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of increase (decrease) in loans from another Federal Home Loan Bank (FHLBank).

+ References

No definition available.

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- Definition

The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

+ References

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 210.9-03.13,16)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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