Supplemental Stockholders' Equity Information - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortizations	$ (230,147)	$ (245,195)	$ (473,819)	$ (484,554)
Total reclassification, before tax	29,443	34,586	68,303	66,046
Income tax expense	5,781	9,415	11,787	10,719
Total reclassification, net of tax	$ 23,662	$ 25,171	56,516	$ 55,327
Amounts reclassified from accumulated other comprehensive loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassification, before tax			12,628
Income tax expense			3,390
Total reclassification, net of tax			9,238
Amounts reclassified from accumulated other comprehensive loss | Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortizations			(3,251)
Amounts reclassified from accumulated other comprehensive loss | Amortization of actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortizations			$ 15,879