Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities Schedule of Credit Default Swaps, Receive Protection (Details)

v3.6.0.2
Derivative Instruments and Hedging Activities Schedule of Credit Default Swaps, Receive Protection (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2014
USD ($)
Derivative [Line Items]      
Derivative, Notional Amount $ (21,998,381) $ (18,802,500) $ (48,115,523)
Credit Default Swap, Buying Protection [Member]      
Derivative [Line Items]      
Derivative, Average Implied Credit Spread 183.60    
Derivative, Notional Amount $ (125,000)    
Derivative, Fair Value, Net (703)    
Derivative, Cost (4,322)    
Derivative, Unrealized Gains (Losses) $ (5,025)    
Maturity Date, 06/20/2016 [Member] | Credit Default Swap, Buying Protection [Member]      
Derivative [Line Items]      
Derivative, Maturity Date Jun. 20, 2016    
Derivative, Average Implied Credit Spread 105.50    
Derivative, Notional Amount $ (100,000)    
Derivative, Fair Value, Net (502)    
Derivative, Cost (260)    
Derivative, Unrealized Gains (Losses) $ (762)    
Maturity Date, 12/20/2016 [Member] | Credit Default Swap, Buying Protection [Member]      
Derivative [Line Items]      
Derivative, Maturity Date Dec. 20, 2016    
Derivative, Average Implied Credit Spread 496.00    
Derivative, Notional Amount $ (25,000)    
Derivative, Fair Value, Net (201)    
Derivative, Cost (4,062)    
Derivative, Unrealized Gains (Losses) (4,263)    
Derivative Financial Instruments, Liabilities [Member]      
Derivative [Line Items]      
Derivative, Notional Amount (1,362,384) (3,543,593)  
Derivative, Fair Value, Net $ 7,285 $ 12,501