RETIREMENT PLANS, COSTS OF RETIREMENT PLANS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
401(k) plan expense	$ 524	$ 457	$ 374
Qualified noncontributory defined benefit retirement plan
Defined Benefit Plan Disclosure [Line Items]
Plan expense	$ 1,039	$ 1,048	$ 1,054