v3.8.0.1
Investments - Net Investment Income (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Schedule of Investments [Line Items]        
Investment income $ 42,750 $ 37,446 $ 129,078 $ 112,413
Investment expenses (1,927) (1,780) (5,586) (5,122)
Net investment income 40,823 35,666 123,492 107,291
Fixed maturities [Member]        
Schedule of Investments [Line Items]        
Investment income 40,369 35,769 123,849 108,018
Cash and cash equivalents [Member]        
Schedule of Investments [Line Items]        
Investment income 899 506 1,328 1,147
Loans to related party [Member]        
Schedule of Investments [Line Items]        
Investment income 913 599 2,441 1,729
Other [Member]        
Schedule of Investments [Line Items]        
Investment income $ 569 $ 572 $ 1,460 $ 1,519