Fair Value of Financial Instruments - Quantitative Information About Recurring Level 3 Fair Value of Financial Instruments (Details) $ in Thousands	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Securities available for sale, fair value	$ 796,799	$ 647,974
Valuation Technique, Discounted Cash Flow [Member] \| Junior Subordinated Debentures [Member]
Borrowings	$ 51,578	$ 43,136
Valuation Technique, Discounted Cash Flow [Member] \| Weighted Average [Member] \| Measurement Input, Discount Rate [Member] \| Junior Subordinated Debentures [Member]
Liabilities, Weighted average	2.9	4.2
Trust Preferred Securities [Member] \| Valuation Technique, Discounted Cash Flow [Member]
Securities available for sale, fair value	$ 1,548	$ 1,295
Trust Preferred Securities [Member] \| Valuation Technique, Discounted Cash Flow [Member] \| Weighted Average [Member] \| Measurement Input, Discount Rate [Member]
Assets, Weighted average	2.9	4.2

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

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Value of input used to measure debt instrument, including, but not limited to, convertible and non-convertible debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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Value of input used to measure 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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