Earnings Per Share - Common Stock Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Jan. 01, 2017		Oct. 02, 2016		Jul. 03, 2016		Apr. 03, 2016		Jan. 03, 2016	[1]	Sep. 27, 2015		Jun. 28, 2015		Mar. 29, 2015		Jan. 01, 2017		Jan. 03, 2016		Dec. 28, 2014
Earnings Per Share [Abstract]
Net earnings	$ 19.8		$ 80.9		$ 8.9		$ 11.2		$ 34.2		$ 9.1		$ 6.8		$ 3.7		$ 120.8		$ 53.8	[2]	$ 23.7
Less: Earnings allocated to participating securities																	(2.6)		(1.4)		(0.7)
Net earnings available to common shareholders																	$ 118.2		$ 52.4		$ 23.0
Average common shares outstanding (millions)
Basic (in shares)																	38.1		37.8	[2]	37.5
Dilutive share awards (in shares)																	0.3		0.1		0.0
Diluted (in shares)																	38.4		37.9	[2]	37.5
Basic earnings per share on common stock (in dollars per share)	$ 0.51	[3]	$ 2.08	[3]	$ 0.23	[3]	$ 0.29	[3]	$ 0.88	[3]	$ 0.23	[3]	$ 0.18	[3]	$ 0.10	[3]	$ 3.10	[3]	$ 1.39	[2],[3]	$ 0.61
Diluted earnings per share on common stock (in dollars per share)	$ 0.51	[3]	$ 2.06	[3]	$ 0.23	[3]	$ 0.29	[3]	$ 0.88	[3]	$ 0.23	[3]	$ 0.18	[3]	$ 0.10	[3]	$ 3.08	[3]	$ 1.39	[2],[3]	$ 0.61

[1] Fourth Quarter 2015 included 14 weeks.

[2] Fiscal year included 53 weeks.

[3] Earnings per share amounts for each quarter are required to be computed independently and may not equal the amounts computed for the total year.