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Business Combination & Asset Purchase - Additional Information (Detail) |  |  |  |  | 3 Months Ended | 12 Months Ended |
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Oct. 01, 2021 USD ($) Office $ / shares shares | Apr. 30, 2021 USD ($) Office $ / shares shares | Nov. 16, 2020 USD ($) shares | Jan. 01, 2019 USD ($) Office $ / shares shares | Dec. 31, 2021 USD ($) Loan shares | Sep. 30, 2021 Loan | Jun. 30, 2019 Loan | Dec. 31, 2021 USD ($) shares | Dec. 31, 2020 USD ($) shares | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Nov. 30, 2020 USD ($) Client
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares outstanding | shares |  |  |  |  | 14,063,999 |  |  | 14,063,999 | 12,230,000 |  |  |
Remaining economic useful life |  |  |  |  |  |  |  | 7 years |  |  |  |
Goodwill |  |  |  |  | $ 80,434,000 |  |  | $ 80,434,000 | $ 47,340,000 |  |  |
Amortization expense |  |  |  |  |  |  |  | 677,000 | 720,000 | $ 727,000 |  |
Custar |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Amortization expense |  |  |  |  |  |  |  |  | 160,000 | 167,000 |  |
Customer Lists [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Amortization expense |  |  |  |  |  |  |  | 123,000 | 16,000 |  |  |
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 | $ 22.40 |  |  |  |  |  |  |  |  |  |  |
Total consideration for acquisition | $ 100,312,000 |  |  |  |  |  |  |  |  |  |  |
Cash paid for acquisition | 59,234,000 |  |  |  |  |  |  | 59,234,000 |  |  |  |
Stock issued for acquisition | 41,078,000 |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 1,700,000 |  |  |  |
Goodwill | 25,220,000 |  |  |  |  |  |  |  |  |  |  |
Fair value of assets acquired |  |  |  |  | 334,700,000 |  |  | 334,700,000 |  |  |  |
Gross principal and contractual interest |  |  |  |  | 403,300,000 |  |  | 403,300,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | 5,600,000 |  |  | $ 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 |  |  | $ 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 |  |  | $ 218,000 |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, amortization period |  |  |  |  |  |  |  | 2 years 7 months 6 days |  |  |  |
Fair value adjustment of loans acquired and accounted | $ 237,200 |  |  |  | $ 189,800 |  |  | $ 189,800 |  |  |  |
Number of commercial purchased credit impaired loans paid off | Loan |  |  |  |  | 2 |  |  |  |  |  |  |
Number of consumer purchased credit impaired loans paid off | Loan |  |  |  |  | 1 |  |  |  |  |  |  |
Discount recognized at acquisition related to commercial purchased credit-impaired loans |  |  |  |  |  |  |  | 47,400 |  |  |  |
Business acquisition, number of shares issued to purchase assets | shares | 1,833,845 |  |  |  |  |  |  |  |  |  |  |
Fair value of assets acquired |  |  |  |  | $ 334,700,000 |  |  | 334,700,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | 5,600,000 |  |  | 5,600,000 |  |  |  |
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 |  |  |  |  |  |  |  |  |  |  |
Perpetual Federal Savings Bank [Member] | Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 131,500 |  |  |  |
Perpetual Federal Savings Bank [Member] | Data Processing [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 444,900 |  |  |  |
Perpetual Federal Savings Bank [Member] | Consulting Fees [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 636,800 |  |  |  |
Perpetual Federal Savings Bank [Member] | Other General and Administrative Expenses [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 488,300 |  |  |  |
Ossian State Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of full-service offices | Office |  | 2 |  |  |  |  |  |  |  |  |  |
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 acquisition |  | 20,001,000 |  |  |  |  |  |  |  |  |  |
Goodwill |  | 7,874,000 |  |  |  |  |  |  |  |  |  |
Fair value of assets acquired |  |  |  |  | 52,400,000 |  |  | 52,400,000 |  |  |  |
Gross principal and contractual interest |  |  |  |  | 63,700,000 |  |  | 63,700,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | 1,100,000 |  |  | $ 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 |  |  | $ 59,000 |  |  |  |
Fair value for certificate of deposit, amortization period |  |  |  |  |  |  |  | 1 year 4 months 24 days |  |  |  |
Fair value adjustment of loans acquired and accounted |  | $ 324,800 |  |  | 320,600 |  |  | $ 320,600 |  |  |  |
Discount recognized at acquisition related to commercial purchased credit-impaired loans |  |  |  |  |  |  |  | 4,200 |  |  |  |
Goodwill deductible for tax purpose, period |  | 15 years |  |  |  |  |  |  |  |  |  |
Number of agricultural real purchased credit impaired loans paid off | Loan |  |  |  |  |  | 2 |  |  |  |  |  |
Fair value of assets acquired |  |  |  |  | 52,400,000 |  |  | 52,400,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | 1,100,000 |  |  | 1,100,000 |  |  |  |
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 |  |  |  |  |  |  |  |  |  |
Ossian Financial Services, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Cash paid for acquisition |  |  |  |  |  |  |  | 20,001,000 |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 2,200,000 | 42,500 |  |  |
Ossian Financial Services, Inc. [Member] | Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 694,100 |  |  |  |
Ossian Financial Services, Inc. [Member] | Data Processing [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 938,900 |  |  |  |
Ossian Financial Services, Inc. [Member] | Consulting Fees [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 255,200 | 12,500 |  |  |
Ossian Financial Services, Inc. [Member] | Other General and Administrative Expenses [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 255,000.0 | 30,000.0 |  |  |
Ossian Financial Services, Inc. [Member] | ATM Expense [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  | 13,800 |  |  |  |
Bank of Geneva [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of full-service offices | Office |  |  |  | 6 |  |  |  |  |  |  |  |
Bank of Geneva [Member] | Core Deposits [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Recognition of core deposit intangible asset with acquired purchase |  |  |  | $ 3,900,000 |  |  |  |  |  |  |  |
Limberlost Bancshares, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Cash payment for exchange of each share | $ / shares |  |  |  | $ 8,465.00 |  |  |  |  |  |  |  |
Common stock, shares outstanding | shares |  |  |  | 1,000 |  |  |  |  |  |  |  |
Share price | $ / shares |  |  |  | $ 38.49 |  |  |  |  |  |  |  |
Total consideration for acquisition |  |  |  | $ 78,902,000 |  |  |  |  |  |  |  |
Cash paid for acquisition |  |  |  | 8,465,000 |  |  |  |  |  | 8,465,000 |  |
Stock issued for acquisition |  |  |  | 70,437,000 |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | 1,280,000 | $ 742,100 |
Goodwill |  |  |  | 43,266,000 |  |  |  |  |  |  |  |
Fair value of assets acquired |  |  |  |  | 257,200,000 |  |  | 257,200,000 |  |  |  |
Gross principal and contractual interest |  |  |  |  | 359,200,000 |  |  | 359,200,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | 4,700,000 |  |  | $ 4,700,000 |  |  |  |
Loan receivable weighted average life |  |  |  |  |  |  |  | 70 months |  |  |  |
Business combination, premises and equipment written down value |  |  |  |  |  |  |  | $ 1,200,000 |  |  |  |
Business combination, average remaining life |  |  |  |  |  |  |  | 16 years 9 months |  |  |  |
Fair value for certificate of deposit, valuation amount |  |  |  |  | 500,000 |  |  | $ 500,000 |  |  |  |
Fair value for certificate of deposit, amortization period |  |  |  |  |  |  |  | 1 year 6 months |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, valuation amount |  |  |  |  | 1,300,000 |  |  | $ 1,300,000 |  |  |  |
Fair value of Federal Home Loan Bank (FHLB) advances, amortization period |  |  |  |  |  |  |  | 2 years 3 months 18 days |  |  |  |
Fair value adjustment of loans acquired and accounted |  |  |  | $ 2,118,000 |  |  |  |  | $ 0 | 62,000 |  |
Number of commercial purchased credit impaired loans paid off | Loan |  |  |  |  |  |  | 2 |  |  |  |  |
Discount recognized at acquisition related to commercial purchased credit-impaired loans |  |  |  |  |  |  |  |  |  | 1,985,000 |  |
Business acquisition, number of shares issued to purchase assets | shares |  |  |  | 1,830,000 |  |  |  |  |  |  |  |
Business combination, acquisition related costs percentage |  |  |  |  |  |  |  |  |  |  | 98.40% |
Fair value of assets acquired |  |  |  |  | 257,200,000 |  |  | $ 257,200,000 |  |  |  |
Acquisition expected to be uncollectible |  |  |  |  | $ 4,700,000 |  |  | $ 4,700,000 |  |  |  |
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 |  |  |  |  |  |  |  |
Limberlost Bancshares, Inc. [Member] | Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | 163,000.0 |  |
Limberlost Bancshares, Inc. [Member] | Data Processing [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | 867,600 | $ 58,600 |
Limberlost Bancshares, Inc. [Member] | Consulting Fees [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | 19,300 | 340,000 |
Limberlost Bancshares, Inc. [Member] | Other General and Administrative Expenses [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | 199,800 | $ 331,500 |
Limberlost Bancshares, Inc. [Member] | ATM Expense [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business combination, acquisition related costs |  |  |  |  |  |  |  |  |  | $ 31,400 |  |
Adams County Financial Resources [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Total consideration for acquisition |  |  | $ 825,000 |  |  |  |  |  |  |  |  |
Stock issued for acquisition |  |  | $ 825,000 |  |  |  |  |  |  |  |  |
Business acquisition, number of shares issued to purchase assets | 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 |  |  |  |  |  |  |  |  |

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- Definition Number of shares of equity interests issued or issuable to acquire entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 + 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 -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472 + 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 -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472 + 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 -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472 + Details
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -URI http://asc.fasb.org/extlink&oid=123586518&loc=d3e1043-128460 + 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 -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477 + Details
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- Definition Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477 + Details
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- Definition Remaining amortization period of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 926 -SubTopic 20 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=120154696&loc=d3e54445-107959 + Details
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