| 
           Income Taxes (Details Textual) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | 9 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
| 
           Sep. 30, 2014 
         | 
        
           Sep. 30, 2013 
         | 
        
           Sep. 30, 2014 
         | 
        
           Sep. 30, 2013 
         | 
        
           Sep. 30, 2014
 
          Common Stock [Member]
 
          Liberty Media [Member] 
         | 
        
           Dec. 31, 2014
 
          Scenario, Forecast [Member] 
         | 
      |
| Related Party Transaction [Line Items] | ||||||
| Income tax expense | $ 89,044 | $ 61,158 | $ 252,614 | $ 216,857 | ||
| Effective income tax percentage | 41.90% | 39.10% | ||||
| Valuation allowance | $ 7,699 | $ 7,699 | ||||
| Related party ownership percentage (greater than 50%) | 50.00% | |||||
| X | ||||||||||
| 
             
- Definition 
          Related Party Transaction, Related Party Ownership Percentage No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
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- Details 
          
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