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           Debt (Details Textual) (USD $) 
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        3 Months Ended | 6 Months Ended | 1 Months Ended | 1 Months Ended | 3 Months Ended | 6 Months Ended | 1 Months Ended | 3 Months Ended | 6 Months Ended | 1 Months Ended | 1 Months Ended | 1 Months Ended | 3 Months Ended | 1 Months Ended | 6 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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           Jun. 30, 2012 
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           Jun. 30, 2011 
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           Jun. 30, 2012 
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           Jun. 30, 2011 
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           Mar. 31, 2010
 
          8.75% Senior Notes due 2015 [Member] 
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           Jun. 30, 2012
 
          8.75% Senior Notes due 2015 [Member] 
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           Dec. 31, 2011
 
          8.75% Senior Notes due 2015 [Member] 
         | 
        
           Aug. 31, 2009
 
          9.75% Senior Secured Notes due 2015 [Member] 
         | 
        
           Jun. 30, 2012
 
          9.75% Senior Secured Notes due 2015 [Member] 
         | 
        
           Jun. 30, 2012
 
          9.75% Senior Secured Notes due 2015 [Member] 
         | 
        
           Dec. 31, 2011
 
          9.75% Senior Secured Notes due 2015 [Member] 
         | 
        
           Jul. 31, 2008
 
          13% Senior Notes due 2013 [Member] 
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           Jun. 30, 2012
 
          13% Senior Notes due 2013 [Member] 
         | 
        
           Jun. 30, 2012
 
          13% Senior Notes due 2013 [Member] 
         | 
        
           Dec. 31, 2011
 
          13% Senior Notes due 2013 [Member] 
         | 
        
           Aug. 31, 2008
 
          7% Exchangeable Senior Subordinated Notes due 2014 [Member] 
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           Jun. 30, 2012
 
          7% Exchangeable Senior Subordinated Notes due 2014 [Member] 
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           Dec. 31, 2011
 
          7% Exchangeable Senior Subordinated Notes due 2014 [Member] 
         | 
        
           Oct. 31, 2010
 
          7.625% Senior Notes due 2018 [Member] 
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           Jun. 30, 2012
 
          7.625% Senior Notes due 2018 [Member] 
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           Dec. 31, 2011
 
          7.625% Senior Notes due 2018 [Member] 
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           Feb. 28, 2011
 
          3.25% Convertible Notes due 2011 [Member] 
         | 
        
           Jun. 30, 2011
 
          3.25% Convertible Notes due 2011 [Member] 
         | 
        
           Jan. 31, 2011
 
          11.25% Senior Secured Notes due 2013 [Member] 
         | 
        
           Jun. 30, 2012
 
          11.25% Senior Secured Notes due 2013 [Member] 
         | 
        
           Jun. 30, 2009
 
          11.25% Senior Secured Notes due 2013 [Member] 
         | 
      |
| Debt (Textual) [Abstract] | ||||||||||||||||||||||||||
| Interest rate on instrument | 8.75% | 9.75% | 13.00% | 7.00% | 7.625% | 3.25% | 11.25% | |||||||||||||||||||
| Aggregate principal amount issued | $ 800,000,000 | $ 257,000,000 | $ 778,500,000 | $ 550,000,000 | $ 700,000,000 | |||||||||||||||||||||
| Due date of interest on note | semi-annually in arrears on April 1 and October 1 of each year | semi-annually in arrears on March 1 and September 1 of each year | semi-annually in arrears on February 1 and August 1 of each year | semi-annually in arrears on June 1 and December 1 of each year | semi-annually in arrears on May 1 and November 1 of each year | |||||||||||||||||||||
| Maturity date of notes | Apr. 01, 2015 | Sep. 01, 2015 | Aug. 01, 2013 | Dec. 01, 2014 | Nov. 01, 2018 | |||||||||||||||||||||
| Proceeds from issuance of debt | 786,000,000 | 244,292,000 | ||||||||||||||||||||||||
| Debt discount | 14,000,000 | 8,435,000 | 9,753,000 | 12,708,000 | 5,308,000 | 5,308,000 | 8,356,000 | 24,616,000 | 24,616,000 | 39,504,000 | 5,058,000 | 5,956,000 | 10,285,000 | 10,898,000 | ||||||||||||
| Principal balance repaid | 38,316,000 | 70,888,000 | 62,729,000 | 96,983,000 | 94,148,000 | |||||||||||||||||||||
| Principal balance repaid inclusive of accrued interest | 169,899,000 | 208,824,000 | 41,875,000 | 77,440,000 | 73,616,000 | 113,226,000 | 40,376,000 | |||||||||||||||||||
| Aggregate loss on extinguishment of notes | (15,650,000) | (1,212,000) | (25,621,000) | (7,206,000) | (4,054,000) | (7,832,000) | (11,596,000) | (17,789,000) | (1,079,000) | (4,915,000) | ||||||||||||||||
| Number of Shares for each $1000 principal amount on conversion (in shares) | 533.3333 | |||||||||||||||||||||||||
| Debt instrument convertible principal amount | $ 1,000 | |||||||||||||||||||||||||
| Conversion price per share (in dollars per share) | $ 1.875 | $ 1.875 | ||||||||||||||||||||||||
| Minimum purchase price for 3.25% Notes in 2011 | 100.75% | |||||||||||||||||||||||||
| Maximum purchase price for 3.25% Notes in 2011 | 100.94% | |||||||||||||||||||||||||
| Maximum consolidated leverage | 6.0 | |||||||||||||||||||||||||