FAIR VALUE MEASUREMENT - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2014	Dec. 31, 2013
Assets measured at fair value:
Restricted cash	$ 2,001	$ 2,087
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Assets measured at fair value:
Total assets measured at fair value	6,812	1,880
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Money Market Funds
Assets measured at fair value:
Cash and cash equivalents	5,007	5
Restricted cash	1,805	1,875
Fair Value, Measurements, Recurring | Fair Value Disclosure, Total
Assets measured at fair value:
Total assets measured at fair value	6,812	1,880
Fair Value, Measurements, Recurring | Fair Value Disclosure, Total | Money Market Funds
Assets measured at fair value:
Cash and cash equivalents	5,007	5
Restricted cash	$ 1,805	$ 1,875