COMMITMENTS AND CONTINGENCIES - Legal Proceedings (Details) $ in Millions	12 Months Ended
	Dec. 27, 2015 USD ($) item
Letter of credit
Additional disclosures
Outstanding letters of credit | $	$ 33.0
"Sacramento Case"
Contingencies
Number of carriers	5,000
Number of phases	3
"Fresno Case"
Contingencies
Number of carriers	3,500
Number of phases	2