SUPPLEMENTAL EQUITY INFORMATION - AOCL (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019	Dec. 29, 2019
Changes in stockholders' equity
Balance at the beginning of the period	$ (576,139)
Amounts reclassified from AOCL	6,735
Other comprehensive income	6,735	$ 22,552
Balance at the end of the period	(569,404)
Amount Reclassified from AOCL
Retirement benefit expense	3,867	10,727
Retained earnings	(2,543,869)		$ (2,365,216)
Net income loss	(178,653)	(41,956)
Minimum Pension and Post-Retirement Liability
Changes in stockholders' equity
Balance at the beginning of the period	(567,670)
Amounts reclassified from AOCL	6,735
Other comprehensive income	6,735
Balance at the end of the period	(560,935)
Minimum Pension and Post-Retirement Liability | Amount Reclassified from AOCL
Amount Reclassified from AOCL
Retirement benefit expense	6,735	$ 4,807
Other Comprehensive Loss Related to Equity Investments
Changes in stockholders' equity
Balance at the beginning of the period	(8,469)
Balance at the end of the period	$ (8,469)