Schedule I - Summary of Investments - Other than Investments in Related Parties (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Summary of investments - other than investments in related parties
Cost or Amortized Cost	$ 1,487,616
Estimated Fair Value	1,571,135
Amount at which shown in the Balance Sheet	1,571,135
Total fixed maturities
Summary of investments - other than investments in related parties
Cost or Amortized Cost	1,187,857
Estimated Fair Value	1,218,279
Amount at which shown in the Balance Sheet	1,218,279
U.S. government and government agencies and authorities
Summary of investments - other than investments in related parties
Cost or Amortized Cost	237,344
Estimated Fair Value	241,788
Amount at which shown in the Balance Sheet	241,788
Obligations of states and political subdivisions
Summary of investments - other than investments in related parties
Cost or Amortized Cost	111,578
Estimated Fair Value	116,302
Amount at which shown in the Balance Sheet	116,302
Corporate and other securities.
Summary of investments - other than investments in related parties
Cost or Amortized Cost	838,935
Estimated Fair Value	860,189
Amount at which shown in the Balance Sheet	860,189
Total equity securities
Summary of investments - other than investments in related parties
Cost or Amortized Cost	211,848
Estimated Fair Value	264,945
Amount at which shown in the Balance Sheet	264,945
Industrial, miscellaneous and all other
Summary of investments - other than investments in related parties
Cost or Amortized Cost	211,848
Estimated Fair Value	264,945
Amount at which shown in the Balance Sheet	264,945
Other invested assets
Summary of investments - other than investments in related parties
Cost or Amortized Cost	87,911
Estimated Fair Value	87,911
Amount at which shown in the Balance Sheet	$ 87,911