ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES - EPS, REVENUE RECOGNITION, CONTRACT BALANCES AND COSTS AND WARRANTY RESERVE (Details) - USD ($) shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Potentially dilutive shares excluded from computation of diluted earnings per share due	8.7
Revenue recognized which was previously deferred	$ 5,600,000	$ 2,000,000.0
Deferred commissions related amortization	$ 241,000	$ 241,000
Minimum
Property, Plant and Equipment [Line Items]
Period fees are due for adjustable rebate contracts	30 days
Warranty coverage period	2 years
Maximum
Property, Plant and Equipment [Line Items]
Period fees are due for adjustable rebate contracts	60 days
Warranty coverage period	5 years
Interactive devices | Minimum
Property, Plant and Equipment [Line Items]
Hardware maintenance services terms (in months)	36 months
Interactive devices | Maximum
Property, Plant and Equipment [Line Items]
Hardware maintenance services terms (in months)	60 months
Non-interactive projectors
Property, Plant and Equipment [Line Items]
Hardware maintenance services terms (in months)	60 months