Supplemental Cash Flow Information- Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Supplemental Cash Flow Elements [Abstract]
Interest paid	$ 1.9	$ 2.7	$ 2.7
Income taxes paid	20.1	24.0	23.5
Non-cash capital expenditures	$ 3.0	$ 1.7	$ 1.8