Other (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jun. 25, 2017	Jul. 01, 2018	Jun. 25, 2017	Dec. 31, 2017
Other Expense [Line Items]
Advertising expense	$ 35.6	$ 25.8	$ 67.2	$ 59.4
Severance liability	10.7		10.7		$ 18.8
Selling, General and Administrative Expenses
Other Expense [Line Items]
Severance costs				20.9
Capitalized Computer Software Costs
Other Expense [Line Items]
Capitalized computer software amortization	3.9	2.7	7.3	5.8
Headquarters Redesign and Consolidation
Other Expense [Line Items]
Costs incurred during the period	1.3	2.0	3.1	4.4
Restructuring costs capitalized in period	5.0	10.0		$ 11.0
Severance | Selling, General and Administrative Expenses
Other Expense [Line Items]
Severance costs	$ 2.2	$ 19.3	$ 4.6