v2.4.0.6
Shareholders' Equity (Details) (USD $)
 0 Months Ended 12 Months Ended 0 Months Ended
Oct. 27, 2011
Jul. 28, 2011
Apr. 27, 2011
Feb. 03, 2011
Aug. 11, 2010
May 05, 2010
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Oct. 31, 2011
Jan. 26, 2012
Dividend Declared [Member]
Aug. 11, 2010
Series A Preferred Stock [Member]
Sep. 01, 2010
Common Stock [Member]
Class of Stock [Line Items]                          
Stock Redeemed or Called During Period, Shares                       76,898  
Stock Redeemed or Called During Period, Value               $ 80,200,000       $ 76,900,000 $ 3,300,000
Payments for Repurchase of Redeemable Preferred Stock                       77,800,000  
Payments for Repurchase of Redeemable Preferred Stock, Accrued and Unpaid Dividends                       919,000  
Reduction of Earnings Available to Common Stockholders Upon Repayment of Preferred Stock         2,300,000                
Declared quarterly cash dividend $ 0.08 $ 0.06 $ 0.05 $ 0.03             $ 0.08    
Stock Repurchase Program, Number of Shares Authorized to be Repurchased                   2,000,000      
Stock Repurchased During Period, Shares             0            
Stock Repurchase Program Number Of Shares Repurchased As Of Balance Sheet Date             64,788            
Special cash dividend payable $ 0.05                   $ 0.29    
Stock Issued During Period, Shares, New Issues           11,040,000              
Stock Issued During Period, New Issues, Price Per Share           $ 21.75              
Stock Issued During Period, Value, New Issues           240,100,000   229,129,000 113,537,000        
Proceeds from Issuance of Common Stock           $ 229,100,000 $ 0 $ 229,129,000 $ 113,537,000