Common Stock Repurchases (Details) (USD $)
Share data in Thousands, unless otherwise specified
1 Months Ended 12 Months Ended
Nov. 27, 2012
Dec. 31, 2012
Short-term Debt [Line Items]    
Proceeds from issuance of convertible notes $ 100,000,000 $ 115,000,000
Common Stock Repurchases (Textual) [Abstract]    
Share repurchase program authorized by Board of Directors   50,000,000
Maximum share repurchasing ability   50,000,000
Common stock shares repurchased   1,900
Cost of common stock shares repurchased   49,270,000
Balance available for repurchase under share repurchase program   700,000
Convertible Notes Payable [Member]
   
Short-term Debt [Line Items]    
Proceeds from issuance of convertible notes   $ 25,000,000