Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares available for issuance under the 2011 Plan (in shares)	3,875,996		3,875,996
Stock options, granted (in shares)			597,093
Stock options, weighted average exercise price (in dollars per share)			$ 47.26
Stock options, weighted average grant date fair value (in dollars per share)			$ 10.35
Assumptions used in Black-Scholes model
Risk-free interest rate (in hundredths)			1.57%
Expected life (in years)			6 years 0 months 0 days
Stock volatility (in hundredths)			22.10%
Dividend yield (in hundredths)			0.80%
Granted, PVS awards (in shares)			130,486
Grant date fair value, PVS awards (in dollars per share)			$ 47.27
Number of shares of common stock per PVS award (in shares)	1		1
Performance period			3 years
PVS payout, Minimum (in hundredths)	0.00%		0.00%
PVS payout, Maximum (in hundredths)	200.00%		200.00%
Stock-based compensation expense	$ 4.6	$ 5.0	$ 8.9	$ 10.4