Other (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2017	Jun. 26, 2016	Jun. 25, 2017	Jun. 26, 2016	Dec. 25, 2016
Other Expense [Line Items]
Advertising expense	$ 25.8	$ 20.1	$ 59.4	$ 41.2
Severance liability	30.2		30.2		$ 23.2
Selling, General and Administrative Expenses
Other Expense [Line Items]
Severance costs	19.3	1.7	20.9	5.3
Capitalized Computer Software Costs
Other Expense [Line Items]
Capitalized computer software amortization	2.7	2.7	5.8	5.7
Headquarters Redesign and Consolidation
Other Expense [Line Items]
Costs incurred during the period	2.0		4.4
Restructuring costs capitalized in period	10.0		11.0
Severance
Other Expense [Line Items]
Additional costs expected in the second half of 2017	$ 6.0		$ 6.0
Relocation and Severance-related Charges | Streamlining of International Print Operations
Other Expense [Line Items]
Costs incurred to date		$ 11.9		$ 11.9