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Business Combination and Asset Purchase - Additional Information (Detail) |  |  |  |  |  | 3 Months Ended | 9 Months Ended |  |
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Oct. 01, 2022 USD ($) Office $ / shares shares | Oct. 01, 2021 USD ($) Office $ / shares shares | Apr. 30, 2021 USD ($) Office $ / shares shares | Nov. 16, 2020 USD ($) shares | Jan. 01, 2019 USD ($) shares $ / shares | Sep. 30, 2023 USD ($) shares | Sep. 30, 2023 USD ($) shares | Sep. 30, 2022 USD ($) | Dec. 31, 2022 USD ($) shares | Nov. 30, 2020 USD ($) Client
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Common stock, shares outstanding | shares |  |  |  |  |  | 14,564,425 | 14,564,425 |  | 14,564,425 |
Goodwill |  |  |  |  |  | $ 86,358,000 | $ 86,358,000 |  | $ 86,358,000 |
Pro-forma operating revenue, net of tax |  |  |  |  |  | 316,000 | 1,000,000 |  |  |
Amortization expense |  |  |  |  |  |  | 1,242,000 | $ 597,000 |  |
Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Amortization expense |  |  |  |  |  |  | 1,200,000 | 597,000 |  |
Amortization expense for 2023 |  |  |  |  |  | 1,656,000 | 1,656,000 |  |  |
Customer Lists [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Amortization expense |  |  |  |  |  |  | 92,000 | $ 92,000 |  |
Amortization expense for 2023 |  |  |  |  |  | 123,000 | 123,000 |  |  |
Peoples Federal Savings and Loan [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Number of full-service offices | Office | 3 |  |  |  |  |  |  |  |  |
Common stock issued in exchange of each outstanding share | 0.6597 |  |  |  |  |  |  |  |  |
Cash payment for exchange of each share | $ / shares | $ 24 |  |  |  |  |  |  |  |  |
Minimum number of shares to be exchanged under merger agreement | shares | 758,566 |  |  |  |  |  |  |  |  |
Common stock, shares outstanding | shares | 1,167,025 |  |  |  |  |  |  |  |  |
Share price | $ / shares | $ 26.87 |  |  |  |  |  |  |  |  |
Total consideration for acquisition | $ 23,249,000 |  |  |  |  |  |  |  |  |
Cash paid for the capital stock | 9,806,000 |  |  |  |  |  |  |  |  |
Stock issued for acquisition | 13,446,000 |  |  |  |  |  |  |  |  |
Goodwill | 5,924,000 |  |  |  |  |  |  |  |  |
Fair value of assets acquired | 101,800,000 |  |  |  |  |  |  |  |  |
Gross principal and contractual interest | 116,100,000 |  |  |  |  |  |  |  |  |
Acquisition expected to be uncollectible | $ 0 |  |  |  |  |  |  |  |  |
Loan receivable weighted average life | 44 months 12 days |  |  |  |  |  |  |  |  |
Business combination, premises and equipment written up value | $ 581,000 |  |  |  |  |  |  |  |  |
Business combination, premises and equipment written down value | $ 597,000 |  |  |  |  |  |  |  |  |
Business combination, average remaining life | 12 years 9 months 18 days |  |  |  |  |  |  |  |  |
Fair value for certificate of deposit, valuation amount | $ 662,000 |  |  |  |  |  |  |  |  |
Fair value for certificate of deposit, amortization period | 1 year 1 month 6 days |  |  |  |  |  |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, valuation amount | $ 69,000 |  |  |  |  |  |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, amortization period | 5 years 2 months 12 days |  |  |  |  |  |  |  |  |
Peoples Federal Savings and Loan [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase | $ 6,000,000 |  |  |  |  |  |  |  |  |
Remaining economic useful life | 7 years |  |  |  |  |  |  |  |  |
Recognition of core deposit tangible asset with acquired purchase |  |  |  |  |  |  | 6,000,000 |  |  |
Amortization expense for 2023 |  |  |  |  |  | 861,000 | 861,000 |  |  |
Perpetual Federal Savings Bank [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Number of full-service offices | Office |  | 1 |  |  |  |  |  |  |  |
Common stock issued in exchange of each outstanding share |  | 1.7766 |  |  |  |  |  |  |  |
Cash payment for exchange of each share | $ / shares |  | $ 41.20 |  |  |  |  |  |  |  |
Business acquisition share owned subject to adjustment | shares |  | 1,833,999 |  |  |  |  |  |  |  |
Common stock, shares outstanding | shares |  | 2,470,032 |  |  |  |  |  |  |  |
Share price | $ / shares |  | $ 22.4 |  |  |  |  |  |  |  |
Total consideration for acquisition |  | $ 100,312,000 |  |  |  |  |  |  |  |
Cash paid for the capital stock |  | 59,234,000 |  |  |  |  |  |  |  |
Stock issued for acquisition |  | 41,078,000 |  |  |  |  |  |  |  |
Goodwill |  | 25,220,000 |  |  |  |  |  |  |  |
Fair value of assets acquired |  | 334,700,000 |  |  |  |  |  |  |  |
Gross principal and contractual interest |  | 403,300,000 |  |  |  |  |  |  |  |
Acquisition expected to be uncollectible |  | $ 5,600,000 |  |  |  |  |  |  |  |
Loan receivable weighted average life |  | 52 months |  |  |  |  |  |  |  |
Business combination, premises and equipment written down value |  | $ 4,000 |  |  |  |  |  |  |  |
Business combination, average remaining life |  | 16 years 2 months 12 days |  |  |  |  |  |  |  |
Fair value for certificate of deposit, valuation amount |  | $ 3,900,000 |  |  |  |  |  |  |  |
Fair value for certificate of deposit, amortization period |  | 1 year 7 months 6 days |  |  |  |  |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, valuation amount |  | $ 218,000 |  |  |  |  |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, amortization period |  | 2 years 7 months 6 days |  |  |  |  |  |  |  |
Perpetual Federal Savings Bank [Member] | Building [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Business combination, premises and equipment written down value |  | $ 297,000 |  |  |  |  |  |  |  |
Perpetual Federal Savings Bank [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  | $ 668,000 |  |  |  |  |  |  |  |
Remaining economic useful life |  | 7 years |  |  |  |  |  |  |  |
Amortization expense for 2023 |  |  |  |  |  | 95,000 | 95,000 |  |  |
Ossian State Bank [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Number of full-service offices | Office |  |  | 2 |  |  |  |  |  |  |
Ossian State Bank [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit tangible asset with acquired purchase |  |  |  |  |  |  | 980,200 |  |  |
Ossian Financial Services, Inc. [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Cash payment for exchange of each share | $ / shares |  |  | $ 67.71 |  |  |  |  |  |  |
Common stock, shares outstanding | shares |  |  | 295,388 |  |  |  |  |  |  |
Total consideration for acquisition |  |  | $ 20,001,000 |  |  |  |  |  |  |
Cash paid for the capital stock |  |  | 20,001,000 |  |  |  |  |  |  |
Goodwill |  |  | 7,874,000 |  |  |  |  |  |  |
Fair value of assets acquired |  |  | 52,400,000 |  |  |  |  |  |  |
Gross principal and contractual interest |  |  | 63,700,000 |  |  |  |  |  |  |
Acquisition expected to be uncollectible |  |  | $ 1,100,000 |  |  |  |  |  |  |
Loan receivable weighted average life |  |  | 52 months |  |  |  |  |  |  |
Business combination, premises and equipment written down value |  |  | $ 596,000 |  |  |  |  |  |  |
Business combination, average remaining life |  |  | 39 years |  |  |  |  |  |  |
Fair value for certificate of deposit, valuation amount |  |  | $ 59,000 |  |  |  |  |  |  |
Fair value for certificate of deposit, amortization period |  |  | 1 year 4 months 24 days |  |  |  |  |  |  |
Goodwill deductible for tax purpose, period |  |  | 15 years |  |  |  |  |  |  |
Ossian Financial Services, Inc. [Member] | Building [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Business combination, premises and equipment written down value |  |  | $ 244,000 |  |  |  |  |  |  |
Ossian Financial Services, Inc. [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  |  | $ 980,200 |  |  |  |  |  |  |
Remaining economic useful life |  |  | 7 years |  |  |  |  |  |  |
Amortization expense for 2023 |  |  |  |  |  | $ 140,000 | 140,000 |  |  |
Bank of Geneva [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  |  |  |  |  |  | $ 3,900,000 |  |  |
Remaining economic useful life |  |  |  |  |  | 7 years | 7 years |  |  |
Limberlost Bancshares, Inc. [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Common stock issued in exchange of each outstanding share | shares |  |  |  |  | 1,830 |  |  |  |  |
Cash payment for exchange of each share | $ / shares |  |  |  |  | $ 8,465 |  |  |  |  |
Common stock, shares outstanding | shares |  |  |  |  | 1,000 |  |  |  |  |
Share price | $ / shares |  |  |  |  | $ 38.49 |  |  |  |  |
Total consideration for acquisition |  |  |  |  | $ 78,900,000 |  |  |  |  |
Cash paid for the capital stock |  |  |  |  | 8,500,000 |  |  |  |  |
Stock issued for acquisition |  |  |  |  | 70,400,000 |  |  |  |  |
Goodwill |  |  |  |  | 43,300,000 |  |  |  |  |
Limberlost Bancshares, Inc. [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  |  |  |  | $ 3,900,000 |  |  |  |  |
Remaining economic useful life |  |  |  |  | 7 years |  |  |  |  |
Perpetual Federal Savings Bank [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit tangible asset with acquired purchase |  |  |  |  |  |  | $ 668,000 |  |  |
Adams County Financial Resources [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total consideration for acquisition |  |  |  | $ 825,000 |  |  |  |  |  |
Common stock issued in exchange of each outstanding share | shares |  |  |  | 40,049 |  |  |  |  |  |
Assets under management amount |  |  |  |  |  |  |  |  |  | $ 83,000,000
Number of clients assets under management | Client |  |  |  |  |  |  |  |  |  | 450
Adams County Financial Resources [Member] | Customer Lists [Member] |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  |  |  | $ 800,000 |  |  |  |  |  |
Remaining economic useful life |  |  |  | 6 years 6 months |  |  |  |  |  |
Amortization expense for 2023 |  |  |  |  |  | $ 123,000 | $ 123,000 |  |  |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482686/350-30-45-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482665/350-30-50-2 + Details
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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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479907/805-20-50-5 + Details
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- Definition Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination. + References No definition available. + Details
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- Definition Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (h)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479328/805-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (h)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479328/805-10-50-2 + Details
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- Definition For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the best estimate at the acquisition date of the contractual cash flows not expected to be collected, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479907/805-20-50-1 + Details
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- Definition Fair value of acquired receivable from business combination, excluding certain loans and debt securities acquired in transfer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479907/805-20-50-1 + Details
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- Definition For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts receivable, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479907/805-20-50-1 + Details
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- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 30 -Paragraph 8 -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479637/805-30-30-8 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479581/805-30-50-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 30 -Paragraph 7 -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479637/805-30-30-7 + Details
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