Employee Benefit Plans (Schedule of Net Benefit Costs, Pension Plans) (Details) - Pension Plans, Defined Benefit - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6,598	$ 6,853	$ 4,951
Interest cost	16,546	16,146	16,707
Expected return on plan assets	(24,561)	(28,939)	(26,401)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	1,547	0	0
Actuarial loss (gain)	27,134	17,146	(7,085)
Amortization of prior service cost	(152)	375	(195)
Net periodic benefit cost	$ 24,018	$ 11,581	$ (12,023)