Schedule I (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 527,183	$ 450,074
Investments	528,647	452,714
US Government and Government Agencies and Authorities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	151,656	81,973
Available-for-sale Securities, Debt Securities	149,952	81,647
Foreign Government Debt Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	2,031	2,038
Available-for-sale Securities, Debt Securities	2,061	2,075
US States and Political Subdivisions Debt Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	170,636	154,004
Available-for-sale Securities, Debt Securities	169,112	155,905
Public Utility, Bonds [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	7,687	8,398
Available-for-sale Securities, Debt Securities	7,730	8,493
All Other Corporate Bonds [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	164,424	148,170
Available-for-sale Securities, Debt Securities	164,536	146,758
Redeemable Preferred Stock [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,182	1,832
Available-for-sale Securities, Debt Securities	1,125	1,820
Debt Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	497,616
Fixed Maturities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	497,616	396,415
Available-for-sale Securities, Debt Securities	494,516	396,698
Mutual Fund [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis		26,357
Available-for-sale Securities, Equity Securities		26,343
Public Utility, Equities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	1,343	1,342
Available-for-sale Securities, Equity Securities	1,507	1,352
Other Common Stock [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	19,815	18,624
Available-for-sale Securities, Equity Securities	24,048	20,694
Common Stock
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Securities, Equity Securities	24,048
Nonredeemable Preferred Stock [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	2,916	2,356
Available-for-sale Securities, Equity Securities	2,843	2,417
Equity Securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	24,074	48,679
Available-for-sale Securities, Equity Securities	28,398	50,806
Other Long-term Investments
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Available-for-sale Securities, Amortized Cost Basis	5,493	4,980
Other Long-term Investments	$ 5,733	$ 5,210