COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		$ (3,130)	$ (1,689)	$ (2,139)	$ (2,710)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		(1,508)	326	374
Amounts reclassified from accumulated other comprehensive loss		67	124	197
Other Comprehensive Income (Loss), Net of Tax		(1,441)	450	571
Unrealized Gains and Losses on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		583	(266)	(427)	(220)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		849	161	(207)
Amounts reclassified from accumulated other comprehensive loss		0	0	0
Other Comprehensive Income (Loss), Net of Tax		849	161	(207)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		(2,484)	(712)	(1,237)	(1,936)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		(1,839)	401	502
Amounts reclassified from accumulated other comprehensive loss	[1]	67	124	197
Other Comprehensive Income (Loss), Net of Tax		(1,772)	525	699
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		(1,229)	(711)	(475)	$ (554)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		(518)	(236)	79
Amounts reclassified from accumulated other comprehensive loss		0	0	0
Other Comprehensive Income (Loss), Net of Tax		$ (518)	$ (236)	$ 79

[1] This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2019, 2018 and 2017.