FINANCIAL INSTRUMENTS AND FAIR VALUE- Assets liabilities measured at fair value on recurring basis (Detail 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	$ 18,804	$ 11,796
Fair Value, Measurements, Recurring | Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	477	477
Fair Value, Measurements, Recurring | Marketable securities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	18,327	11,319
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	18,804	11,796
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) | Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	477	477
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) | Marketable securities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets	18,327	11,319
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Marketable securities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Marketable securities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets