Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 1.4	$ 1.7	$ 2.4
Additions for prior years’ tax positions	0.0	0.1	0.1
Reductions for prior years’ tax positions	0.0	0.0	(0.7)
Additions for settlements	0.0	0.0	0.0
Reductions for settlements	0.0	0.0	0.0
Reductions for expiration of statutes	(0.2)	(0.4)	(0.1)
Balance at end of the year	$ 1.2	$ 1.4	$ 1.7