EMPLOYEE STOCK PLANS - Stock Option Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Number of Shares
Outstanding at December 31, 2011 (in shares)	7,614
Granted (in shares)	1,296
Exercised (in shares)	(7)
Canceled or forfeited (in shares)	(1,071)
Outstanding at September 30, 2012 (in shares)	7,832
Vested and expected to vest at September 30, 2012 (in shares)	7,122
Exercisable at September 30, 2012 (in shares)	3,921
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Outstanding at December 31, 2012 (in usd per share)	$ 3.34
Weighted Average Exercise Price, Granted (in usd per share)	$ 1.23
Weighted Average Exercise Price, Exercised (in usd per share)	$ 0.76
Weighted Average Exercise Price, Canceled or forfeited (in usd per share)	$ 2.57
Weighted-Average Exercise Price, Outstanding at September 30, 2012 (in usd per share)	$ 3.10
Weighted Average Exercise Price, Vested and expected to vest at September 30, 2012 (in usd per share)	$ 3.26
Weighted Average Exercise Price, Exercisable at September 30, 2012 (in usd per share)	$ 4.70
Weighted Average Remaining Term
Weighted Average Remaining Term, Outstanding at September 30, 2012	4 years 2 months 12 days
Weighted Average Remaining Term, Vested and expected to vest at September 30, 2012	3 years 10 months 24 days
Weighted Average Remaining Term, Exercisable at September 30, 2012	2 years
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding at September 30, 2012	$ 1,255
Aggregate Intrinsic Value, Vested and expected to vest at September 30, 2012	1,109
Aggregate Intrinsic Value, Exercisable at September 30, 2012	$ 339