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Fair Value Measurements - Quantitative and Qualitative Information (Details)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Quantitative information about Level 3 fair value measurements
Mortgage servicing rights, fair value	$ 9,726,000	$ 10,344,000
Securities available-for-sale, at fair value	1,190,854,000	1,192,829,000
Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Mortgage servicing rights, fair value	9,726,000	10,344,000
Securities available-for-sale, at fair value	16,168,000	15,329,000
Asset-backed Securities
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	63,947,000	68,436,000
States and political subdivisions
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	224,795,000	227,065,000
Collateralized mortgage obligations
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	384,271,000	392,544,000
Fair Value, Measurements, Recurring
Quantitative information about Level 3 fair value measurements
Mortgage servicing rights, fair value	9,726,000	10,344,000
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Mortgage servicing rights, fair value	9,726,000	10,344,000
Fair Value, Measurements, Recurring | Asset-backed Securities
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	63,947,000	68,436,000
Fair Value, Measurements, Recurring | Asset-backed Securities | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	3,300,000	2,270,000
Fair Value, Measurements, Recurring | States and political subdivisions
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	224,795,000	227,065,000
Fair Value, Measurements, Recurring | States and political subdivisions | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	12,868,000	13,059,000
Fair Value, Measurements, Recurring | Collateralized mortgage obligations
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	384,271,000	392,544,000
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Asset-backed Securities | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	$ 3,300,000	$ 2,270,000
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Asset-backed Securities | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Minimum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.049	0.056
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Asset-backed Securities | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Maximum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.049	0.056
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Asset-backed Securities | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Weighted Average
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.049	0.056
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Mortgage servicing rights, fair value	$ 9,726,000	$ 10,344,000
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Minimum
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.090	0.090
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Maximum
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.110	0.110
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Weighted Average
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.090	0.090
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3
Quantitative information about Level 3 fair value measurements
Securities available-for-sale, at fair value	$ 12,868,000	$ 13,059,000
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Minimum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.052	0.032
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Maximum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.061	0.054
Fair Value, Measurements, Recurring | Measurement Input, Discount Rate | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Weighted Average
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.061	0.047
Fair Value, Measurements, Recurring | Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Minimum
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.000	0.051
Fair Value, Measurements, Recurring | Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Maximum
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.381	0.330
Fair Value, Measurements, Recurring | Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Weighted Average
Quantitative information about Level 3 fair value measurements
Servicing Asset, Measurement Input	0.073	0.066
Fair Value, Measurements, Recurring | Measurement Input, Liquidity Premium | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Minimum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.005	0.005
Fair Value, Measurements, Recurring | Measurement Input, Liquidity Premium | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Maximum
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.005	0.005
Fair Value, Measurements, Recurring | Measurement Input, Liquidity Premium | States and political subdivisions | Discounted Cash Flow Valuation Technique | Fair Value, Inputs, Level 3 | Weighted Average
Quantitative information about Level 3 fair value measurements
Debt Securities, Measurement Input	0.005	0.005

X

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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+ References

No definition available.

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481229/860-50-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481260/860-50-45-2

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Value of input used to measure servicing asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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