v2.4.0.8
Shareholders' Equity (Details Textual) (USD $)
1 Months Ended 3 Months Ended 6 Months Ended 1 Months Ended
Apr. 30, 2013
Feb. 28, 2013
Jul. 31, 2012
Apr. 30, 2012
Feb. 29, 2012
Jun. 30, 2013
Mar. 31, 2013
Jun. 30, 2012
Mar. 31, 2012
Jun. 30, 2013
Jun. 30, 2012
Dec. 31, 2012
Jul. 31, 2013
Subsequent Event [Member]
Feb. 28, 2013
Management Awards [Member]
Feb. 28, 2013
Performance Shares [Member]
Feb. 28, 2013
Minimum [Member]
Performance Shares [Member]
Feb. 28, 2013
Maximum [Member]
Performance Shares [Member]
Shareholders Equity (Textual) [Abstract]                                  
Authorized common stock (in shares)           100,000,000       100,000,000   100,000,000          
Authorized preferred stock (in shares)           50,000,000       50,000,000   50,000,000          
Quarterly dividend declared, per share (USD per share)           $ 0.25 $ 0.25 $ 0.125 $ 0.125 $ 0.5 $ 0.25            
Dividend declared           $ 15,400,000 $ 15,400,000 $ 7,700,000 $ 7,700,000                
Dividend payments 15,400,000   7,700,000 7,700,000     0     15,320,000 15,270,000   15,400,000        
Dividends Payable           15,400,000   7,700,000   15,400,000 7,700,000            
Total authorizations which remain available for use           135,100,000       135,100,000              
Share-based compensation           2,400,000   2,900,000   4,708,000 5,072,000            
Tax benefits from share-based compensation expense           $ 800,000   $ 1,000,000   $ 1,600,000 $ 1,800,000            
Awards in period (in shares)                           39,000 146,000    
Fair value of each unit awarded (USD per share)                           $ 46.97 $ 46.97    
Award vesting period                           3 years 3 years    
Award payout rate                             125.00% 75.00% 125.00%
Shares issued in period for share-based compensation (in shares)                           32,000 120,000    
Bonus compensation shares issued (in shares)   41,000     19,000                        
Federal statutory income tax rate           35.00%   35.00%   35.00% 35.00%