(Schedule of Fair Value of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 27, 2019	Dec. 28, 2018
Assets:
Other Assets, Fair Value Disclosure	$ 26.2
Fair Value, Measurements, Recurring
Assets:
Debt and equity securities held in rabbi trusts	30.6	$ 33.1
Total assets at fair value	56.8	33.1
Liabilities:
Deferred compensation liabilities	39.2	38.5
Contingent consideration	69.3	151.4
Total liabilities at fair value	108.5	189.9
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Debt and equity securities held in rabbi trusts	21.0	22.4
Other Assets, Fair Value Disclosure	26.2
Total assets at fair value	47.2	22.4
Liabilities:
Deferred compensation liabilities	0.0	0.0
Contingent consideration	0.0	0.0
Total liabilities at fair value	0.0	0.0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Debt and equity securities held in rabbi trusts	9.6	10.7
Other Assets, Fair Value Disclosure	0.0
Total assets at fair value	9.6	10.7
Liabilities:
Deferred compensation liabilities	39.2	38.5
Contingent consideration	0.0	0.0
Total liabilities at fair value	39.2	38.5
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Debt and equity securities held in rabbi trusts	0.0	0.0
Other Assets, Fair Value Disclosure	0.0
Total assets at fair value	0.0	0.0
Liabilities:
Deferred compensation liabilities	0.0	0.0
Contingent consideration	69.3	151.4
Total liabilities at fair value	$ 69.3	$ 151.4