Income Taxes - Reconciliation of Income Tax Provision (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jun. 25, 2017	Mar. 26, 2017	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Income Tax Disclosure [Abstract]
Income tax (benefit) at federal statutory rate									$ (17.8)	$ (18.3)	$ (15.6)
State taxes, net of federal tax benefit and valuation allowance									0.7	0.2	(0.2)
Difference in tax rates between U.S. and foreign									0.0	0.1	(0.7)
Increase (decrease) in valuation allowance									(45.6)	19.1	0.0
Nondeductible expense									1.1	0.7	0.8
Increase in reserve for uncertain tax positions									1.3	2.2	0.9
Changes to indefinite life items and separate state deferred taxes									(2.2)	4.1	3.4
One-time transition tax on previously undistributed foreign earnings									6.2	0.0	0.0
Goodwill impairment									8.1	0.0	0.0
Impact related to the 2017 Tax Act									40.0	0.0	0.0
Total	$ (11.7)	$ 0.2	$ 1.8	$ 1.5	$ 0.8	$ 1.9	$ 1.8	$ 3.6	$ (8.2)	$ 8.1	$ (11.4)