LONG-TERM OBLIGATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 21, 2020	Dec. 20, 2020	Dec. 31, 2017
Line of Credit Facility [Line Items]
Cash and temporary investments	$ 57,521	$ 26,072	$ 27,037			$ 21,895
First Tennessee Bank National Association | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility				$ 50,000
Interest expense on credit facility	235	684	$ 512
Line of credit outstanding borrowings	$ 0	4,998
Debt instrument description of non-default rate of interest	LIBOR Market Index Rate plus 1.00% or 1.25% per annum, depending on the leverage ratio
Minimum tangible net worth required for compliance				$ 190,000	$ 160,000
Tangible net worth	$ 271,000
First Tennessee Bank National Association | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Interest rate	1.14%
First Tennessee Bank National Association | Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Non-usage fee for current loan agreement in annual amount percentage	0.15%
First Tennessee Bank National Association | Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Variable interest rate in addition to reference rate	1.00%
First Tennessee Bank National Association | Revolving Credit Facility | Maximum
Line of Credit Facility [Line Items]
Non-usage fee for current loan agreement in annual amount percentage	0.35%
First Tennessee Bank National Association | Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Variable interest rate in addition to reference rate	1.25%
Jige International S.A. | Banque Europeenne Du Credit Mutuel
Line of Credit Facility [Line Items]
Maturity date	Sep. 30, 2020
Unsecured debt, long-term obligations due within one year		$ 368