| 
           Subsequent Events (Details) (USD $) 
        In Thousands, except Share data, unless otherwise specified  | 
        1 Months Ended | 12 Months Ended | 1 Months Ended | 1 Months Ended | |||
|---|---|---|---|---|---|---|---|
| 
           Dec. 31, 2011 
         | 
        
           Dec. 31, 2011 
         | 
        
           Dec. 31, 2010 
         | 
        
           Dec. 31, 2009 
         | 
        
           May 31, 2010
 
          2007 Term Loan
 
          Loans Payable [Member] 
         | 
        
           Jun. 30, 2011
 
          2007 Term Loan
 
          Loans Payable [Member] 
         | 
        
           Jan. 31, 2012
 
          2007 Term Loan
 
          Loans Payable [Member]
 
          Repayment of Debt [Member] 
         | 
      |
| Subsequent Event [Line Items] | |||||||
| Long-term Debt, Current Maturities | $ 298,000 | ||||||
| Issuances of stock, shares | 41,745,000 | ||||||
| Repayments of Long-term Debt | $ 0 | $ 104,681 | $ 30,030 | $ 102,000 | $ 298,200 | ||
| X | ||||||||||
| 
             
- Definition 
          Total of the portions of the carrying amounts as of the balance sheet date of long-term debt, which may include notes payable, bonds payable, debentures, mortgage loans, and commercial paper, which are scheduled to be repaid within one year or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Number of new stock issued during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Details 
          
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