Stock Repurchases (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 132.6
Treasury Stock, Shares, Acquired	199,766
Treasury Stock, Value, Acquired, Cost Method	$ 17.4