v2.4.0.8
Investments - Schedule of Investments Reconciliation (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2013
Dec. 31, 2012
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost $ 2,620,107 $ 2,475,202
Other Investments, Original or amortized cost 4,500 2,599
Total investments, Original or amortized cost 2,624,607 2,477,801
Available-for-sale securitites, Gross unrealized gains 102,742 151,460
Other investments, Gross unrealized gains 506 353
Investments, Gross unrealized gains 103,248 151,813
Available-for-sale securities, Gross unrealized losses (48,544) (7,965)
Other investments, Gross unrealized losses 0 (51)
Investments, Gross unrealized losses (48,544) (8,016)
Total Investments, Fair Value 2,674,305 2,618,697
Other investments 5,006 2,901
Total investments 2,679,311 2,621,598
U.S. treasury bonds [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 16,629 42,671
Available-for-sale securitites, Gross unrealized gains 745 1,260
Available-for-sale securities, Gross unrealized losses 0 0
Total Investments, Fair Value 17,374 43,931
U.S. agency bonds – mortgage-backed [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 1,138,860 962,649
Available-for-sale securitites, Gross unrealized gains 16,083 30,998
Available-for-sale securities, Gross unrealized losses (24,230) (1,473)
Total Investments, Fair Value 1,130,713 992,174
U.S. agency bonds – other [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 7,205 11,682
Available-for-sale securitites, Gross unrealized gains 1,093 1,407
Available-for-sale securities, Gross unrealized losses 0 0
Total Investments, Fair Value 8,298 13,089
Non-U.S. government bonds [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 64,992 55,169
Available-for-sale securitites, Gross unrealized gains 2,734 2,264
Available-for-sale securities, Gross unrealized losses (444) 0
Total Investments, Fair Value 67,282 57,433
Other mortgage-backed securities [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 22,624 23,167
Available-for-sale securitites, Gross unrealized gains 97 901
Available-for-sale securities, Gross unrealized losses (59) 0
Total Investments, Fair Value 22,662 24,068
Corporate bonds [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 1,324,209 1,247,260
Available-for-sale securitites, Gross unrealized gains 81,247 113,386
Available-for-sale securities, Gross unrealized losses (23,810) (6,492)
Total Investments, Fair Value 1,381,646 1,354,154
Municipal bonds [Member]
    
Schedule of Investments [Line Items]    
Fixed Maturities, available-for-sale, Amortized cost 45,588 132,604
Available-for-sale securitites, Gross unrealized gains 743 1,244
Available-for-sale securities, Gross unrealized losses (1) 0
Total Investments, Fair Value $ 46,330 $ 133,848