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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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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 loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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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.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	Dec. 31, 2018 USD ($) subsidary segment	Mar. 31, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Number of subsidiaries \| subsidary	6
Goodwill impairment	$ 0
Number of reportable operating segments \| segment	1
Core Deposits
Property, Plant and Equipment [Line Items]
Core deposit amortization period	10 years
Maximum \| Bank Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Maximum \| Equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Maximum \| Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum \| Software
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum \| Automobiles
Property, Plant and Equipment [Line Items]
Estimated useful life	4 years
Accumulated Other Comprehensive Loss \| Accounting Standards Update 2018-02
Property, Plant and Equipment [Line Items]
Reclassification of certain tax effects from accumulated other comprehensive income	$ (486,000)
Retained Earnings \| Accounting Standards Update 2018-02
Property, Plant and Equipment [Line Items]
Reclassification of certain tax effects from accumulated other comprehensive income	$ 486,000
Expected impact \| Accounting Standards Update 2016-02
Property, Plant and Equipment [Line Items]
Expected increase to recorded assets		$ 12,000,000
Expected increase to recorded liabilities		$ 12,000,000