Off-Balance Sheet Loan Commitments - Summary of Financial Instruments with Off-Balance Sheet Risk - (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Unused lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments, off balance sheet risk, Fixed Rate	$ 35,764	$ 49,057
Financial instruments, off balance sheet risk, Variable Rate	594,305	444,028
Financial instruments, off balance sheet risk	630,069	493,085
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments, off balance sheet risk, Fixed Rate	5,382	3,017
Financial instruments, off balance sheet risk, Variable Rate	3,259	3,781
Financial instruments, off balance sheet risk	8,641	6,798
Commitments to purchase loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments, off balance sheet risk, Fixed Rate	0
Financial instruments, off balance sheet risk, Variable Rate	51,747	22,004
Financial instruments, off balance sheet risk	51,747	22,004
Mortgage warehouse commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments, off balance sheet risk, Fixed Rate	0	0
Financial instruments, off balance sheet risk, Variable Rate	318,972	340,502
Financial instruments, off balance sheet risk	$ 318,972	$ 340,502

Loans and leases receivable commitments.

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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

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788

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- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788

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