FAIR VALUE - RECURRING (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Marketable Securities	$ 107,972
Recurring
Marketable Securities	107,972		$ 116,748
Available-for-sale Securities
Marketable Securities	107,972	$ 116,748
Corporate
Marketable Securities	20,938	20,064
Corporate | Recurring
Marketable Securities	20,938		20,064
Corporate | Level 2 | Recurring
Marketable Securities	20,438	19,564
Corporate | Level 3 | Recurring
Marketable Securities	500	500
US Agencies
Marketable Securities	14,496	15,970
US Agencies | Recurring
Marketable Securities	14,496		15,970
US Agencies | Level 2 | Recurring
Marketable Securities	14,496	15,970
US Agencies - MBS
Marketable Securities	34,526	32,840
US Agencies - MBS | Recurring
Marketable Securities	34,526		32,840
US Agencies - MBS | Level 2 | Recurring
Marketable Securities	34,526	32,840
Obligations of states and political subdivisions
Marketable Securities	38,012	47,874
Obligations of states and political subdivisions | Recurring
Marketable Securities	38,012		$ 47,874
Obligations of states and political subdivisions | Level 2 | Recurring
Marketable Securities	37,024	46,886
Obligations of states and political subdivisions | Level 3 | Recurring
Marketable Securities	$ 903	$ 988