Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Earnings Per Share [Abstract]
Net earnings	$ 6.8	$ 2.8	$ 10.5	$ 5.3
Less: earnings allocated to participating securities	(0.2)	(0.1)	(0.3)	(0.2)
Net earnings available to common shareholders	$ 6.6	$ 2.7	$ 10.2	$ 5.1
Basic earnings per share on common stock (in dollars per share)	$ 0.18	$ 0.07	$ 0.27	$ 0.14
Diluted earnings per share on common stock (in dollars per share)	$ 0.18	$ 0.07	$ 0.27	$ 0.14
Average common shares outstanding (millions):
Basic (in shares)	37.7	37.4	37.7	37.4
Diluted (in shares)	37.8	37.4	37.8	37.4