Investments Maturity Distribution of Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Due in One Year or Less, Amortized Cost Basis	$ 38,553
Available-for-sale Securities, Debt Maturities, Due After One Year Through Five Years, Amortized Cost Basis	108,931
Available-for-sale Securities, Debt Maturities, Due After Five Years Through Ten Years, Amortized Cost Basis	113,784
Available-for-sale Securities, Debt Maturities, Due After Ten Years, Amortized Cost Basis	523,666
Available-for-sale Debt Securities, Amortized Cost Basis	784,934	$ 714,137
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Due in One Year or Less, Fair Value	39,140
Available-for-sale Securities, Debt Maturities, Due After One Year Through Five Years, Fair Value	113,330
Available-for-sale Securities, Debt Maturities, Due After Five Years Through Ten Years, Fair Value	122,978
Available-for-sale Securities, Debt Maturities, Due After Ten Years, Fair Value	560,025
Available-for-sale Debt Securities, Fair Value	835,473
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount [Abstract]
Held-to-maturity Securities, Debt Maturities, Due in One Year or Less, Amortized Cost Basis	4,185
Held-to-maturity Securities, Debt Maturities, Due After One Year Through Five Years, Amortized Cost Basis	38,928
Held-to-maturity Securities, Debt Maturities, Due After Five Years Through Ten Years, Amortized Cost Basis	56,368
Held-to-maturity Securities, Debt Maturities, Due After Ten Years, Amortized Cost Basis	156,684
Held-to-maturity Securities	256,165	259,953
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Held-to-maturity Securities, Debt Maturities, Due in One Year or Less, Fair Value	4,206
Held-to-maturity Securities, Debt Maturities, Due After One Year Through Five Years, Fair Value	41,368
Held-to-maturity Securities, Debt Maturities, Due After Five Years Through Ten Years, Fair Value	60,490
Held-to-maturity Securities, Debt Maturities, Due After Ten Years, Fair Value	163,987
Held-to-maturity Securities, Fair Value	270,051	264,966
Total Fixed maturity securities, Amortized Cost	1,041,099	974,090
Total Fixed Maturity Securities, Fair Value	$ 1,105,524	$ 1,000,614