Net Investment Income (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income $ 48,913 $ 45,174 $ 47,540
Fixed Maturities [Member]      
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income 37,139 36,256 38,559
Equity Securities [Member]      
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income 9,666 7,146 7,660
Policy Loans [Member]      
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income 619 557 545
Cash Equivalents and Interest-Bearing Deposits [Member]      
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income 257 143 117
Other [Member]      
Interest and/or dividend income from [Abstract]      
Interest and/or dividend income $ 1,232 $ 1,072 $ 659