FAIR VALUE MEASUREMENT - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2015	Dec. 31, 2014
Assets measured at fair value:
Restricted cash	$ 1,974	$ 1,993
Fair Value, Measurements, Recurring | Fair Value Disclosure, Total
Assets measured at fair value:
Total assets measured at fair value	16,814	8,813
Fair Value, Measurements, Recurring | Money Market Funds | Fair Value Disclosure, Total
Assets measured at fair value:
Cash and cash equivalents	15,008	7,007
Restricted cash	1,806	1,806
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Assets measured at fair value:
Total assets measured at fair value	16,814	8,813
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Money Market Funds
Assets measured at fair value:
Cash and cash equivalents	15,008	7,007
Restricted cash	$ 1,806	$ 1,806