SUPPLEMENTAL EQUITY INFORMATION - AOCL (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018
Changes in stockholders' equity
Balance at the beginning of the period	$ (604,289)	$ (449,369)
Other comprehensive income (loss) before reclassifications	7,021
Amounts reclassified from AOCL	21,129	(154,920)
Other comprehensive income		(154,920)
Other comprehensive income	28,150	(56,530)
Balance at the end of the period	(576,139)	(604,289)
Amount Reclassified from AOCL
Retirement benefit expense	23,715	11,114
Retained earnings	(2,365,216)	(1,954,132)
Net income loss	(411,107)	(79,757)
Amount Reclassified from AOCL
Amount Reclassified from AOCL
Retained earnings		98,390
Net income loss	(21,129)	154,920
Minimum Pension and Post-Retirement Liability
Changes in stockholders' equity
Balance at the beginning of the period	(595,820)	(442,406)
Other comprehensive income (loss) before reclassifications	7,021
Amounts reclassified from AOCL	21,129	(153,414)
Other comprehensive income		(153,414)
Other comprehensive income	28,150
Balance at the end of the period	(567,670)	(595,820)
Minimum Pension and Post-Retirement Liability | Amount Reclassified from AOCL
Amount Reclassified from AOCL
Retirement benefit expense	21,129	(56,530)
Other Comprehensive Loss Related to Equity Investments
Changes in stockholders' equity
Balance at the beginning of the period	(8,469)	(6,963)
Amounts reclassified from AOCL		(1,506)
Other comprehensive income		(1,506)
Balance at the end of the period	$ (8,469)	$ (8,469)