VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	$ 1,285	$ 1,868	$ 2,173
Additional Charges to Costs and Expenses	(21)	26	(37)
Deductions	(177)	(609)	(268)
Balance at End of Period	1,087	1,285	1,868
Product returns
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	280	383	272
Additional Charges to Costs and Expenses	(171)	(230)	245
Deductions	59	127	(134)
Balance at End of Period	168	280	383
Inventory reserves
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	4,665	4,544	10,070
Additional Charges to Costs and Expenses	980	509	(3,879)
Deductions	(572)	(388)	(1,647)
Balance at End of Period	5,073	4,665	4,544
Warranty reserves
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	718	643	529
Additional Charges to Costs and Expenses	1,043	1,111	1,162
Deductions	(1,191)	(1,036)	(1,048)
Balance at End of Period	$ 570	$ 718	$ 643