The number of branch offices operated by the entity.

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Represents the number of loan production offices operated by the company.

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Represents the number of personalized technology centers with interactive teller machines (ITM's) operated by the company.

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The amount of increase reclassified from Retained Earnings into AOCI due to the impact of the newly enacted tax rate and its effects on unrealized gains on marketable securities.

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 50
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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Note 1 - Summary of Significant Accounting Policies (Details Textual)		12 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2018 $ / shares	Sep. 30, 2017 USD ($)
Number of Branches		42
Number of Personalized Technology Centers		3
Number of Loan Production Offices		3
Number of Operating Segments		1
Other than Temporary Impairment Losses, Investments		$ 0	$ 0	$ 0
Goodwill, Impaired, Accumulated Impairment Loss						$ 0
AOCI Attributable to Parent [Member] \| Accounting Standards Update 2018-02 [Member] \| Subsequent Event [Member]
Reclassification of Tax Effects from AOCI to Retained Earnings Due to Change in Enacted Tax Rate	$ 39,000
Retained Earnings [Member] \| Accounting Standards Update 2018-02 [Member] \| Subsequent Event [Member]
Reclassification of Tax Effects from AOCI to Retained Earnings Due to Change in Enacted Tax Rate	$ (39,000)
Minimum [Member]
Property, Plant and Equipment, Useful Life		3 years
Finite-Lived Intangible Asset, Useful Life		12 years
Maximum [Member]
Property, Plant and Equipment, Useful Life		40 years
Finite-Lived Intangible Asset, Useful Life		13 years
One-to-Four-Family Residential [Member] \| Real Estate Portfolio Segment [Member]
Mortgage Loans in Process of Foreclosure, Amount		$ 1,000,000
Scenario, Forecast [Member] \| Merger With Arvest [Member] \| Arvest Bank [Member]
Business Acquisition, Share Price \| $ / shares					$ 10.28