v2.4.0.6
Stockholders' Equity (Details) (USD $)
1 Months Ended 12 Months Ended
May 14, 2012
Dec. 31, 2012
Dec. 31, 2011
May 11, 2012
Nov. 10, 2006
Stockholders' Equity (Textual) [Abstract]          
Stock authorized to be repurchased under share repurchase program       4,000,000 1,000,000
Repurchased shares 2,774,250 2,774,250 10,124    
Repurchase of Common Stock Authorized Remaining   1,225,750      
Aggregate purchase price of repurchased shares $ 66,638,000 $ 66,638,000      
Share repurchased per share price $ 24.02 $ 24.02      
Share repurchased, percentage of outstanding shares 11.80%