Goodwill and Other Intangible Assets (Schedule of Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 28, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,150,025	$ 1,130,750
Accumulated Amortization	820,776	766,311
Intangible assets, net	329,249	364,439
Customer Lists
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	494,615	500,914
Accumulated Amortization	312,044	271,211
Purchased software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	354,228	364,144
Accumulated Amortization	337,811	353,722
Internal use software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	207,696	174,572
Accumulated Amortization	123,280	99,272
Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	42,951	41,731
Accumulated Amortization	28,961	26,574
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	50,535	49,389
Accumulated Amortization	$ 18,680	$ 15,532