Fair Value Measurements (Financial Assets and Liabilities Carried at Fair Value) (Details) - USD ($) $ in Millions	Sep. 28, 2018	Dec. 31, 2017
Assets:
Available-for-sale securities	$ 40.3	$ 45.4
Liabilities:
Deferred compensation plans	65.4	62.9
Quoted Prices in Active Market (Level 1)
Assets:
Available-for-sale securities	0.0	0.0
Liabilities:
Deferred compensation plans	0.0	0.0
Significant Other Observable Inputs (Level 2)
Assets:
Available-for-sale securities	40.3	45.4
Liabilities:
Deferred compensation plans	65.4	62.9
Significant Unobservable Inputs (Level 3)
Assets:
Available-for-sale securities	0.0	0.0
Liabilities:
Deferred compensation plans	$ 0.0	$ 0.0