Share-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
Share-Based Compensation
Stock based compensation expense	$ 1.1	$ 1.1	$ 2.8	$ 2.4
Stock options
Assumptions used to determine value of the shares purchased under the stock purchase plan using Black-Scholes option pricing model
Expected annual dividend rate (as a percent)			1.33%
Risk-free interest rate (as a percent)			1.50%
Average expected life			5 years 9 months 18 days
Expected volatility of common stock (as a percent)			0.427%
Forfeiture rate (as a percent)			0.00%
Weighted average fair value of option grants (in dollars per share)			$ 4.41
Restricted Stock | Directors
Stock Compensation
Granted (in shares)			44,631
2010 Incentive Plan | Stock options
Stock Compensation
Granted (in shares)			248,008
2010 Incentive Plan | Restricted Stock
Stock Compensation
Granted (in shares)			305,212
Assumptions used to determine value of the shares purchased under the stock purchase plan using Black-Scholes option pricing model
Vesting period			3 years
Granted (in dollars per share)			$ 12.10