v2.4.0.6
Derivative Instruments (Gain (Loss) Recognized In The Consolidated Statements Of Operations Related To Its Derivative Instruments) (Details) (USD $)
In Thousands, unless otherwise specified
0 Months Ended 3 Months Ended
Jan. 20, 2011
Mar. 31, 2012
Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   $ (27,684) $ 5,506
Net Investment Income [Member] | Interest Rate Futures [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   1,030 (654)
Net Investment Income [Member] | Credit Default Swap [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   558 722
Net Foreign Exchange (Losses) Gains [Member] | Foreign Currency Forward Contracts, Underwriting and Non-investment Operations [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   3,552 [1] 7,799 [1]
Net Foreign Exchange (Losses) Gains [Member] | Foreign Currency Forward Contracts, Investment Operations [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   (4,248) [2] (13,400) [2]
Net Foreign Exchange (Losses) Gains [Member] | Foreign Currency Forward Contracts, Energy And Risk Operations [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   137 [3] (436) [3]
Other (Loss) Income [Member] | Energy And Weather Contracts [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives   (28,713) 8,500
Other (Loss) Income [Member] | Platinum Warrant [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain (loss) recognized on derivatives $ 3,000 $ 0 $ 2,975
[1] Contracts used to manage foreign currency risks in underwriting and non-investment operations.
[2] Contracts used to manage foreign currency risks in investment operations.
[3] Contracts used to manage foreign currency risks in energy and risk operations.