EMPLOYEE STOCK PLANS - Stock Option Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Number of Shares
Outstanding at December 31, 2011 (in shares)	6,489
Granted (in shares)	1,385
Exercised (in shares)	(165)
Canceled or forfeited (in shares)	(1,029)
Outstanding at September 30, 2012 (in shares)	6,680
Vested and expected to vest at September 30, 2012 (in shares)	6,242
Exercisable at September 30, 2012 (in shares)	4,149
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Outstanding at December 31, 2012 (in usd per share)	$ 4.37
Weighted Average Exercise Price, Granted (in usd per share)	$ 2.61
Weighted Average Exercise Price, Exercised (in usd per share)	$ 1.06
Weighted Average Exercise Price, Canceled or forfeited (in usd per share)	$ 4.79
Weighted-Average Exercise Price, Outstanding at September 30, 2012 (in usd per share)	$ 4.02
Weighted Average Exercise Price, Vested and expected to vest at September 30, 2012 (in usd per share)	$ 4.14
Weighted Average Exercise Price, Exercisable at September 30, 2012 (in usd per share)	$ 4.98
Weighted Average Remaining Term
Weighted Average Remaining Term, Outstanding at September 30, 2012	3 years 8 months 12 days
Weighted Average Remaining Term, Vested and expected to vest at September 30, 2012	3 years 7 months 6 days
Weighted Average Remaining Term, Exercisable at September 30, 2012	2 years 6 months
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding at September 30, 2012	$ 137
Aggregate Intrinsic Value, Vested and expected to vest at September 30, 2012	134
Aggregate Intrinsic Value, Exercisable at September 30, 2012	$ 120