Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016	Jul. 27, 2015
Net (loss) income
Net income	$ 27.2	$ 28.6	$ 48.9	$ 44.8
Shares
Shares (in shares)	34,500,000	34,500,000	34,500,000	34,400,000
Per Share Amount
Net income (in dollars per share)	$ 0.79	$ 0.83	$ 1.42	$ 1.30
Dilutive securities, principally common stock options
Common stock equivalents (in shares)				100,000
Net (loss) income
Net income	$ 27.2	$ 28.6	$ 48.9	$ 44.8
Weighted average number of shares:
Shares (in shares)	34,500,000	34,500,000	34,500,000	34,500,000
Securities not included in the computation of diluted EPS
Net income (in dollars per share)	$ 0.79	$ 0.83	$ 1.42	$ 1.30
Shares repurchased
Options to purchase shares of Class A common stock	100,000		100,000	200,000
Number of shares repurchased			141,786	359,000
Cost of shares repurchased			$ 9.0	$ 17.6
Class A
Shares repurchased
Total value of shares of the entity's Class A common stock authorized to be repurchased					$ 100.0
Remaining authorized repurchase amount	$ 47.1		$ 47.1
July 27, 2015 | Class A
Shares repurchased
Number of shares repurchased		91,500	72,674
Cost of shares repurchased		$ 5.2	$ 4.5