FAIR VALUE MEASUREMENTS (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Liabilities
Derivatives	$ 51	$ 64
Recurring basis | Level 1
Assets
Total	15,660
Recurring basis | Level 1 | Money market funds
Assets
Total	15,660
Recurring basis | Level 2
Assets
Total	76,607
Recurring basis | Level 2 | Government-sponsored enterprise securities
Assets
Total	8,623
Recurring basis | Level 2 | Commercial paper
Assets
Total	20,644
Recurring basis | Level 2 | Corporate notes
Assets
Total	47,340
Recurring basis | Level 3
Liabilities
Derivatives	51
Recurring basis | Total
Assets
Total	92,267
Liabilities
Derivatives	51
Recurring basis | Total | Money market funds
Assets
Total	15,660
Recurring basis | Total | Government-sponsored enterprise securities
Assets
Total	8,623
Recurring basis | Total | Commercial paper
Assets
Total	20,644
Recurring basis | Total | Corporate notes
Assets
Total	$ 47,340