EMPLOYEE BENEFITS - Contributions (Details) - USD ($)	1 Months Ended		3 Months Ended	6 Months Ended
	May 31, 2016	Feb. 29, 2016	Jun. 26, 2016	Jun. 26, 2016	Dec. 27, 2015
Medical cost trend rates
Financing obligations			$ 53,139,000	$ 53,139,000	$ 32,398,000
Proceeds from sale of real property location	$ 34,300,000
Pension plan
Medical cost trend rates
Value of contributions to plan		$ 47,100,000
Required pension contribution		$ 0
Term of leases entered into for property contributed to pension plan		11 years
Gain or loss recognized on the contribution of property				0
Aggregate Annual Rent Payments On Contributed Property		$ 3,500,000
Other Operating Income (Expense)
Medical cost trend rates
(Loss) on sale of real property location			$ (1,100,000)	$ (1,100,000)