EMPLOYEE STOCK PLANS - Stock Option Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
Jul. 01, 2012
Number of Shares
Outstanding at December 31, 2011 (in shares)	6,489
Granted (in shares)	1,260
Exercised (in shares)	(132)
Canceled or forfeited (in shares)	(596)
Outstanding at July 1, 2012 (in shares)	7,021
Vested and expected to vest at July 1, 2012 (in shares)	6,513
Exercisable at July 1,2012 (in shares)	4,336
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)	$ 2.78
Weighted Average Exercise Price, Exercised (in usd per share)	$ 1.13
Weighted Average Exercise Price, Canceled or forfeited (in usd per share)	$ 4.68
Weighted-Average Exercise Price, Outstanding at July 1, 2012 (in usd per share)	$ 4.12
Weighted Average Exercise Price, Vested and expected to vest at July 1, 2012 (in usd per share)	$ 4.24
Weighted Average Exercise Price, Exercisable at July 1, 2012 (in usd per share)	$ 5.10
Weighted Average Remaining Term
Weighted Average Remaining Term, Outstanding at July 1, 2012	3 years 11 months
Weighted Average Remaining Term, Vested and expected to vest at July 1, 2012	3 years 10 months
Weighted Average Remaining Term, Exercisable at July 1, 2012	2 years 8 months
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding at July 1, 2012	$ 827
Aggregate Intrinsic Value, Vested and expected to vest at July 1, 2012	798
Aggregate Intrinsic Value, Exercisable at July 1, 2012	$ 633

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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