ACCOUNTS RECEIVABLE (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Less:
Allowance for doubtful accounts	$ 15,985,000	$ 17,149,000
Accounts receivable, net	104,305,000	101,171,000
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	120,290,000	118,320,000
Less:
Allowance for doubtful accounts	(2,342,000)	(3,051,000)
Allowance for sales returns and rebates	(13,643,000)	(14,098,000)
Large solution sales and certain distributor sales excluded from accounts receivable	$ 10,300,000	$ 16,100,000