FAIR VALUE (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018
Financial Assets:
Estimated Fair Value	$ 266,721,000			$ 242,258,000
Equity investments	2,032,000			1,909,000
Impaired Loans, Fair Value Disclosure [Abstract]
Level 2 to level 1 transfer amount	0	$ 0
Total Gains (Losses)	(1,093,000)	(709,000)
Recurring
Financial Assets:
Obligations of U.S. Government and U.S. Government sponsored enterprises	5,488,000			5,472,000
Mortgage-backed securities, residential	203,938,000			183,192,000
Obligations of states and political subdivisions	48,332,000			44,152,000
Corporate bonds and notes	249,000			247,000
SBA loan pools	8,714,000			9,195,000
Estimated Fair Value	266,721,000			242,258,000
Equity investments	1,198,000			1,075,000
Derivative assets	4,091,000			3,142,000
Financial Liabilities:
Derivative liabilities	4,321,000			3,282,000
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets:
Obligations of U.S. Government and U.S. Government sponsored enterprises	0			0
Mortgage-backed securities, residential	0			0
Obligations of states and political subdivisions	0			0
Corporate bonds and notes	0			0
SBA loan pools	0			0
Estimated Fair Value	0			0
Equity investments	1,198,000			1,075,000
Derivative assets	0			0
Financial Liabilities:
Derivative liabilities	0			0
Recurring | Significant Other Observable Inputs (Level 2)
Financial Assets:
Obligations of U.S. Government and U.S. Government sponsored enterprises	5,488,000			5,472,000
Mortgage-backed securities, residential	203,938,000			183,192,000
Obligations of states and political subdivisions	48,332,000			44,152,000
Corporate bonds and notes	249,000			247,000
SBA loan pools	8,714,000			9,195,000
Estimated Fair Value	266,721,000			242,258,000
Equity investments	0			0
Derivative assets	4,091,000			3,142,000
Financial Liabilities:
Derivative liabilities	4,091,000			3,142,000
Recurring | Significant Unobservable Inputs (Level 3)
Financial Assets:
Obligations of U.S. Government and U.S. Government sponsored enterprises	0			0
Mortgage-backed securities, residential	0			0
Obligations of states and political subdivisions	0			0
Corporate bonds and notes	0			0
SBA loan pools	0			0
Estimated Fair Value	0			0
Equity investments	0			0
Derivative assets	0			0
Financial Liabilities:
Derivative liabilities	230,000			140,000
Impaired Loans: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	2,913,000			1,456,000
Total Gains (Losses)	(1,785,000)		$ 240,000
Impaired Loans: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	0			0
Impaired Loans: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	0			0
Impaired Loans: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	2,913,000			1,456,000
Other real estate owned: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	144,000			574,000
Total Gains (Losses)	0		(14,000)
Other real estate owned: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Other real estate owned: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Other real estate owned: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	144,000			574,000
Commercial mortgages, other | Other real estate owned: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	62,000			213,000
Total Gains (Losses)	0		0
Commercial mortgages, other | Other real estate owned: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Commercial mortgages, other | Other real estate owned: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Commercial mortgages, other | Other real estate owned: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	62,000			213,000
Home equity lines and loans | Other real estate owned: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net				157,000
Total Gains (Losses)			(14,000)
Home equity lines and loans | Other real estate owned: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net				0
Home equity lines and loans | Other real estate owned: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net				0
Home equity lines and loans | Other real estate owned: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net				157,000
Commercial mortgages
Impaired Loans, Fair Value Disclosure [Abstract]
Total Gains (Losses)	(1,289,000)	(125,000)
Commercial mortgages | Commercial mortgages | Impaired Loans: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	2,913,000			1,456,000
Total Gains (Losses)	(1,785,000)		240,000
Commercial mortgages | Commercial mortgages | Impaired Loans: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	0			0
Commercial mortgages | Commercial mortgages | Impaired Loans: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	0			0
Commercial mortgages | Commercial mortgages | Impaired Loans: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total impaired loans	2,913,000			1,456,000
Residential mortgages
Impaired Loans, Fair Value Disclosure [Abstract]
Total Gains (Losses)	9,000	(180,000)
Residential mortgages | Other real estate owned: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	27,000			204,000
Total Gains (Losses)	0		$ 0
Residential mortgages | Other real estate owned: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Residential mortgages | Other real estate owned: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0			0
Residential mortgages | Other real estate owned: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	27,000			$ 204,000
Consumer Loans
Impaired Loans, Fair Value Disclosure [Abstract]
Total Gains (Losses)	229,000	$ (367,000)
Consumer Loans | Home equity lines and loans | Other real estate owned: | Non-recurring
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	55,000
Total Gains (Losses)	0
Consumer Loans | Home equity lines and loans | Other real estate owned: | Non-recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0
Consumer Loans | Home equity lines and loans | Other real estate owned: | Non-recurring | Significant Other Observable Inputs (Level 2)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	0
Consumer Loans | Home equity lines and loans | Other real estate owned: | Non-recurring | Significant Unobservable Inputs (Level 3)
Impaired Loans, Fair Value Disclosure [Abstract]
Total other real estate owned, net	$ 55,000