Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding at beginning of period (in shares)			1,192,680	972,680
Options outstanding at end of period (in shares)	1,343,680	1,192,680	1,343,680	1,192,680
Weighted average exercise price of shares outstanding at beginning of period (in dollars per share)			$ 12.89	$ 10.32
Weighted average exercise price of shares outstanding at end of period (in dollars per share)	$ 13.44	$ 12.89	$ 13.44	$ 12.89
Options exercisable (in shares)	952,055	735,180	952,055	735,180
Weighted average exercise price of shares exercisable (in dollars per share)	$ 12.15	$ 11.69	$ 12.15	$ 11.69
Weighted average remaining term of the stock options outstanding (in years)			6 years 2 months 12 days	7 years 7 months 6 days
Fair value assumptions and methodology [Abstract]
Stock price (in dollars per share)	$ 17.77	$ 24.24	$ 17.77	$ 24.24
Exercise price (in dollars per share)	$ 17.77	$ 24.24	$ 17.77	$ 24.24
Dividend yield (in hundredths)			0.00%	0.00%
Risk free rate (in hundredths)			0.75%	1.89%
Stock-based compensation expense recorded	$ 0.3	$ 0.3	$ 0.6	$ 0.6
Aggregate intrinsic value of options outstanding	9.6		9.6
Closing price of the common stock (in dollars per share)	$ 19.88		$ 19.88
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options grants (in shares)			111,000	180,000
Weighted average exercise price of shares granted (in dollars per share)			$ 17.77	$ 24.82
Vesting period of stock options (in years)			4 years
Stock Issued During Period, Value, Stock Options Exercised			0.9	2.2
Fair value of stock options granted per share (in dollars per share)			$ 8.46	$ 12.44
Fair value assumptions and methodology [Abstract]
Expected term:			6 years 3 months	6 years 3 months
Expected volatility: (in hundredths)			49.50%	50.20%
Remaining unamortized stock-based compensation cost	2.7		2.7
Stock-based compensation cost recognition period (in years)			3 years 1 month 6 days
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options grants (in shares)			40,000	40,000
Weighted average exercise price of shares granted (in dollars per share)			$ 17.77	$ 21.62
Vesting period of stock options (in years)			1 year
Stock Issued During Period, Value, Stock Options Exercised			0.3	0.4
Fair value of stock options granted per share (in dollars per share)			$ 8.09	$ 10.22
Fair value assumptions and methodology [Abstract]
Expected term:			5 years 6 months	5 years 6 months
Expected volatility: (in hundredths)			50.20%	50.80%
Remaining unamortized stock-based compensation cost	$ 0.3		$ 0.3
Stock-based compensation cost recognition period (in years)			11 months