Stock-Based Compensation (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Stock-based compensation expense
Pre-tax compensation expense	$ 17.4	$ 15.7	$ 17.0
Pre-tax compensation expense related to discontinued operations			0.9
The amount of financing cash flows of excess income tax benefits related to share-based compensation expense	$ 15.9	$ 13.2	$ 5.3
Executive Incentive Program
Stock-based compensation
Shares available for grant under the plan | shares	4,460,142
Shares available for issuance under the plan | shares	1,604,716
Stock options
Stock-based compensation
Stock options granted (in shares) | shares	316,345	259,035	283,975
Awards granted (in shares) | shares	316,345
Portion of stock options vesting on the first anniversary	0.3333
Portion of stock options vesting on the second anniversary	0.3333
Portion of stock options vesting on the third anniversary	0.3333
Maximum term life	10 years
Stock-based compensation expense
Pre-tax compensation expense	$ 5.1	$ 4.5	$ 4.9
After-tax compensation expense	$ 3.2	$ 2.8	$ 3.0
Impact on diluted EPS (in dollars per share) | $ / shares	$ 0.05	$ 0.04	$ 0.05
Unrecognized compensation cost related to stock options	$ 3.7
Weighted average period of recognition of unrecognized compensation cost related to stock options	1 year 11 months 12 days
Weighted-average assumptions used to estimate grant date fair value of stock options
Expected dividend yield (as a percent)	1.10%	1.20%	1.20%
Expected life in years	5 years 8 months 16 days	5 years 8 months 27 days	5 years 8 months 16 days
Expected volatility (as a percent)	27.30%	29.30%	32.20%
Risk-free interest rate (as a percent)	1.40%	1.70%	1.00%
Weighted average fair value (in dollars per share) | $ / shares	$ 21.19	$ 19.15	$ 17.58
Restricted stock awards
Stock-based compensation
Awards granted (in shares) | shares	58,040	104,773	71,255
Stock-based compensation expense
Pre-tax compensation expense	$ 5.9	$ 5.1	$ 4.6
Unrecognized compensation cost related to stock options	$ 4.3
Weighted average period of recognition of unrecognized compensation cost related to stock options	1 year 6 months 29 days
Performance share awards
Stock-based compensation
Awards granted (in shares) | shares	58,040	67,970	71,255
Stock-based compensation expense
Pre-tax compensation expense	$ 6.3	$ 6.0	$ 6.5
Unrecognized compensation cost related to stock options	$ 3.7
Weighted average period of recognition of unrecognized compensation cost related to stock options	1 year 8 months 1 day
Restricted Stock Units
Stock-based compensation
Awards granted (in shares) | shares	12,157
Aggregate grant-date fair value of stock options, restricted stock awards, performance share awards and restricted stock units	$ 19.7