STOCKHOLDERS' EQUITY - Schedule of Reclassification from Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Amortization of defined benefit pension and other postretirement plan actuarial losses:
Cost of sales	$ 2,495,773	$ 2,527,863	$ 7,476,731	$ 7,549,367
Interest income	(4,698)	(4,241)	(11,481)	(10,665)
Miscellaneous, net	$ (1,367)	$ (653)	(2,521)	1,781
Total before tax			(592)	32
Tax benefit (expense)			126	(88)
Net income			(466)	(56)
Amount Reclassified from Accumulated Other Comprehensive Loss
Amortization of defined benefit pension and other postretirement plan actuarial losses:
Cost of sales			(74)	(329)
Interest income			466	1,263
Amount Reclassified from Accumulated Other Comprehensive Loss | Union Plan
Amortization of defined benefit pension and other postretirement plan actuarial losses:
Miscellaneous, net			(54)	(36)
Amount Reclassified from Accumulated Other Comprehensive Loss | Legacy GK plans-production employees
Amortization of defined benefit pension and other postretirement plan actuarial losses:
Miscellaneous, net			(290)	(270)
Amount Reclassified from Accumulated Other Comprehensive Loss | Legacy GK plans-administrative employees
Amortization of defined benefit pension and other postretirement plan actuarial losses:
Miscellaneous, net			$ (640)	$ (596)