SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash, Property equipment - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2016	Jan. 01, 2016
Cash and Cash Equivalents
Uninsured deposits	$ 7,845	$ 4,681
Office and other equipment | Minimum
Cash and Cash Equivalents
Property, Plant and Equipment, Useful Life	2 years
Office and other equipment | Maximum
Cash and Cash Equivalents
Property, Plant and Equipment, Useful Life	10 years
Internally developed software
Cash and Cash Equivalents
Property, Plant and Equipment, Useful Life	3 years
Leasehold improvements | Minimum
Cash and Cash Equivalents
Property, Plant and Equipment, Useful Life	3 years
Leasehold improvements | Maximum
Cash and Cash Equivalents
Property, Plant and Equipment, Useful Life	10 years