Employee Benefit Plans (Schedule of Net Benefit Costs, Other Postretirement Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,951	$ 4,337	$ 4,332
Interest cost	16,707	18,638	20,696
Expected return on plan assets	(26,401)	(24,245)	(26,021)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	907
Actuarial loss (gain)	7,085	(15,890)	(12,953)
Amortization of prior service cost	(195)	(210)	(238)
Net periodic benefit cost	(12,023)	14,410	10,815
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	92	101	108
Interest cost	125	142	143
Expected return on plan assets	(1,114)	(1,035)	(1,062)
Defined Benefit Plan, Amortization of Gain (Loss)	(741)	(539)	971
Actuarial loss (gain)	187	(329)
Net periodic benefit cost	$ (1,638)	$ (1,331)	$ 160