SIGNIFICANT ACCOUNTING POLICIES - AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2016	Mar. 29, 2015
Changes in accumulated other comprehensive loss
Balance at the beginning of the period	$ (421,808)
Other comprehensive income (loss) before reclassifications	(495)
Amounts reclassified from AOCL	2,302
Other comprehensive income (loss)	1,807	$ 2,634
Balance at the end of the period	(420,001)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Compensation	102,774	106,672
Provision for income taxes	(10,115)	(7,653)
Net of tax	12,741	11,346
Minimum Pension and Post-Retirement Liability
Changes in accumulated other comprehensive loss
Balance at the beginning of the period	(411,956)
Amounts reclassified from AOCL	2,302
Other comprehensive income (loss)	2,302
Balance at the end of the period	(409,654)
Minimum Pension and Post-Retirement Liability | Amount Reclassified from AOCI
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Compensation	3,837	4,802
Provision for income taxes	(1,535)	(1,921)
Net of tax	2,302	$ 2,881
Other Comprehensive Loss Related to Equity Investments
Changes in accumulated other comprehensive loss
Balance at the beginning of the period	(9,852)
Other comprehensive income (loss) before reclassifications	(495)
Other comprehensive income (loss)	(495)
Balance at the end of the period	$ (10,347)