Income Taxes - Income Tax Provision Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jun. 25, 2017	Jul. 01, 2018	Jun. 25, 2017
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income tax benefit at federal statutory rate	$ (0.8)	$ (2.0)	$ (0.3)	$ (5.0)
State and foreign taxes, net of federal tax benefit and valuation allowance	(0.1)	0.2	0.1	0.4
GILTI	(0.3)	0.0	(0.2)	0.0
Nondeductible expenses and other	(0.3)	0.6	(0.2)	1.0
Impact of deferred tax liabilities for indefinite-lived assets	(0.8)	1.6	(0.4)	2.7
Increase (decrease) in reserves for uncertain tax positions	1.1	(0.1)	1.4	0.0
Increase in federal valuation allowance	1.3	1.0	0.6	3.6
Total income tax provision	$ 0.1	$ 1.3	$ 1.0	$ 2.7