Accounting Policies (Details 5) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		3 Months Ended									12 Months Ended
	Apr. 30, 2013	Jul. 31, 2012	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 16, 2012	Aug. 02, 2011
Net Income
Net income			$ 8.2	$ 15.4	$ 18.9	$ 16.1	$ 15.5	$ 18.7	$ 18.5	$ 15.7		$ 58.6	$ 68.4	$ 66.4
Shares
Weighted average number of shares (in shares)												35,500,000	36,000,000	37,300,000
Per Share Amount
NET INCOME (in dollars per share)			$ 0.23	$ 0.43	$ 0.53	$ 0.45	$ 0.44	$ 0.53	$ 0.51	$ 0.42		$ 1.65	$ 1.90	$ 1.78
Dilutive securities, principally common stock options
Shares												100,000	100,000	200,000
Net Income
Net income												58.6	68.4	66.4
Weighted average number of shares:
Weighted average number of shares												35,600,000	36,100,000	37,500,000
Per Share Amount
NET INCOME (in dollars per share)			$ 0.23	$ 0.43	$ 0.53	$ 0.45	$ 0.44	$ 0.53	$ 0.51	$ 0.42		$ 1.65	$ 1.90	$ 1.78
Securities not included in the computation of diluted EPS
Options to purchase shares of Class A common stock												200,000	200,000	700,000
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	1,000,000
Number of shares of Class A common stock repurchased		2,000,000									1,000,000	454,000
Cost of shares of Class A common stock repurchased		65.8									27.2	23.0
Financial Instruments
Cash flow hedges, fair value			0				0					0	0
Shipping and Handling
Shipping and handling costs included in selling, general and administrative expense												38.4	37.0	36.9
Research and Development
Research and development costs included in selling, general, and administrative expense												$ 21.5	$ 20.4	$ 20.5