Value Creation Plan (Disclosure of costs incurred since the inception of the Value Creation Plan) (Details) - Value Creation Plan [Member] - USD ($) $ in Thousands	Jun. 27, 2020	Dec. 28, 2019	Jun. 29, 2019	Dec. 29, 2018
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	$ 82,735
Cash payments, net	(59,442)
Non-cash adjustments	(19,127)
Balance payable	4,166	$ 4,227	$ 1,901	$ 913
Asset impairments and facility closure costs [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	35,325
Cash payments, net	(10,649)
Non-cash adjustments	(24,575)
Balance payable	101	201	302	477
Employee recruitment, retention and termination costs [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	24,289
Cash payments, net	(25,672)
Non-cash adjustments	5,448
Balance payable	4,065	4,026	1,599	436
Professional fees and temporary labor costs [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred and charged to expense	23,121
Cash payments, net	(23,121)
Non-cash adjustments	0
Balance payable	$ 0	$ 0	$ 0	$ 0