Annual report pursuant to Section 13 and 15(d)

Derivatives (Details 3)

v2.4.0.8
Derivatives (Details 3) (USD $)
0 Months Ended 12 Months Ended
Mar. 23, 2012
Dec. 31, 2012
Dec. 31, 2011
Derivatives      
Gain on early termination of derivative instruments   $ 8,451,000  
Interest rate swaps (Swaps) | Not designated as hedge
     
Derivatives      
Gain on early termination of derivative instruments 8,451,000    
Settlement payments   8,837,000 38,645,000
Unrealized gain related to the change in fair value of derivatives   $ 6,793,000 $ 28,044,000