DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	3 Months Ended										12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Number of reportable segments											3		3		3
Allowance for doubtful accounts	$ 743,000					$ 771,000					$ 743,000		$ 771,000
Other-than-temporary impairment charge											775,000
Net realized (losses) gains on sales of investments											(100,000)		100,000
Net currency exchange gains (losses)											600,000				(200,000)
Foreign currency translation gains (losses)											281,000		(236,000)		(907,000)
Warranty period for workmanship defects											12 months
Numerator [Abstract]
Net earnings	(2,537,000)	[1]	2,600,000	1,463,000	876,000	82,000	1,012,000	(574,000)	[2]	3,244,000	2,402,000		3,764,000		13,649,000
Undistributed earnings (loss)											(817,000)		552,000		10,463,000
Undistributed earnings (loss) allocation - basic and diluted [Abstract]
Undistributed earnings (loss)											(817,000)		552,000		10,463,000
Net earnings allocation basic and diluted [Abstract]
Net earnings	(2,537,000)	[1]	2,600,000	1,463,000	876,000	82,000	1,012,000	(574,000)	[2]	3,244,000	2,402,000		3,764,000		13,649,000
Earnings per share [Abstract]
Research and Development Costs											12,400,000		12,000,000		11,400,000
Impairment charges related to property, plant and equipment											1,400,000
Carrying value of the building and land											1,000,000
Asset write-downs related to property, plant and equipment	300,000										300,000
Class A [Member]
Numerator [Abstract]
Net earnings											377,000		620,000		2,394,000
Less Dividends declared											522,000		522,000		522,000
Undistributed earnings (loss)											(145,000)		98,000		1,872,000
Undistributed earnings (loss) allocation - basic and diluted [Abstract]
Undistributed earnings (loss)											(145,000)		98,000		1,872,000
Net earnings allocation basic and diluted [Abstract]
Net earnings											377,000		620,000		2,394,000
Weighted-average shares outstanding [Abstract]
Weighted average shares outstanding (in shares)											2,174,912		2,174,912		2,174,912
Earnings per share [Abstract]
Common share - basic and diluted (in dollars per share)	$ (0.21)	[1]	$ 0.20	$ 0.11	$ 0.07	$ 0.00	$ 0.08	$ (0.05)	[2]	$ 0.26	$ 0.17	[3]	$ 0.28	[3]	$ 1.10
Class B [Member]
Earnings Per Share [Line Items]
Dividend rate Class B common stock in excess of dividend rate of Class A common stock (in hundredths)											5.00%		5.00%		5.00%
Undistributed earning allocation rate of Class B common stock in excess of Class A common stock (in hundredths)											5.00%		5.00%		5.00%
Numerator [Abstract]
Net earnings											2,025,000		3,144,000		11,255,000
Less Dividends declared											2,697,000		2,690,000		2,664,000
Undistributed earnings (loss)											(672,000)		454,000		8,591,000
Undistributed earnings (loss) allocation - basic and diluted [Abstract]
Undistributed earnings (loss)											(672,000)		454,000		8,591,000
Net earnings allocation basic and diluted [Abstract]
Net earnings											$ 2,025,000		$ 3,144,000		$ 11,255,000
Weighted-average shares outstanding [Abstract]
Weighted average shares outstanding (in shares)											9,624,578		9,597,661		9,504,261
Earnings per share [Abstract]
Common share - basic and diluted (in dollars per share)	$ (0.22)	[1]	$ 0.22	$ 0.13	$ 0.08	$ 0.01	$ 0.09	$ (0.05)	[2]	$ 0.28	$ 0.21	[3]	$ 0.33	[3]	$ 1.18
Class B [Member] | Stock Options [Member]
Earnings per share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)											0		0		14,718
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life											5 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life											3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life											13 years
Buildings and Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life											3 years
Buildings and Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life											39 years

[1] The net loss for the quarter ended December 31, 2012 includes $3.1 million of restructuring charges primarily related to severance charges and the writedown of assets associated with the closure of the Company's Vinita, Oklahoma manufacturing facility.

[2] The net loss for the quarter ended June 30, 2011 includes $2.8 million of net litigation charges related to the SynQor and Halo lawsuits ($2.6 million after tax).

[3] Quarterly amounts of earnings per share may not agree to the total for the year due to rounding.