Accounting Policies (Details 5) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended
	Jul. 31, 2012	Dec. 31, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2013	May 16, 2012
Net income:
Net income		$ (7.7)	$ 22.6	$ 21.3	$ 14.1	$ 8.2	$ 15.4	$ 18.9	$ 16.1	$ 50.3	$ 58.6	$ 68.4
Shares
Weighted average number of shares (in shares)										35,300,000	35,500,000	36,000,000
Per Share Amount
NET INCOME (in dollars per share)		$ (0.22)	$ 0.64	$ 0.60	$ 0.40	$ 0.23	$ 0.43	$ 0.53	$ 0.45	$ 1.42	$ 1.65	$ 1.90
Dilutive securities, principally common stock options
Shares										100,000	100,000	100,000
Net Income
Net income										50.3	58.6	68.4
Weighted average number of shares:
Weighted average number of shares (in shares)										35,400,000	35,600,000	36,100,000
Per Share Amount
NET INCOME (in dollars per share)		$ (0.22)	$ 0.64	$ 0.60	$ 0.40	$ 0.23	$ 0.43	$ 0.53	$ 0.45	$ 1.42	$ 1.65	$ 1.90
Securities not included in the computation of diluted EPS
Options to purchase shares of Class A common stock										300,000	200,000	200,000
Number of shares of the entity's Class A common stock authorized to be repurchased													90.0
Number of shares of the entity's Class A common stock authorized to be repurchased														2,000,000
Number of shares of Class A common stock repurchased	2,000,000									670,000	454,000
Cost of shares of Class A common stock repurchased	65.8									39.6	23.0
Financial Instruments
Cash flow hedges, fair value		0				0				0	0
Shipping and Handling Costs
Shipping, Handling and Transportation Costs										61.8	61.3	58.4
Research and Development Expense.
Research and Development Expense										$ 22.5	$ 21.5	$ 20.4