Fair Value Measurements (Schedule of assets, which are measured on a recurring basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Total fixed income securities	$ 369,738	$ 320,410
Total equity securities	78,368	69,952
Cash equivalents	42,197	65,354
Total assets at fair value	490,303	455,716
U.S. Government and agencies [Member]
Total fixed income securities	14,757	14,383
Obligations of states and political subdivisions [Member]
Total fixed income securities	71,962	64,244
Corporate securities [Member]
Total fixed income securities	160,768	128,434
Residential mortgage-backed securities [Member]
Total fixed income securities	41,904	36,494
Commercial mortgage-backed securities [Member]
Total fixed income securities	30,819	25,655
Asset backed securities [Member]
Total fixed income securities	49,528	51,200
Basic materials [Member]
Total equity securities	1,066	1,285
Communications [Member]
Total equity securities	8,033	7,455
Consumer, cyclical [Member]
Total equity securities	11,047	9,929
Consumer, non-cyclical [Member]
Total equity securities	16,298	14,633
Energy [Member]
Total equity securities	2,089	1,499
Financial [Member]
Total equity securities	6,841	6,235
Industrial [Member]
Total equity securities	15,088	12,733
Technology [Member]
Total equity securities	17,809	16,145
Utility [Member]
Total equity securities	97	38
Level I [Member]
Total fixed income securities
Total equity securities	78,368	69,952
Cash equivalents	42,197	65,354
Total assets at fair value	120,565	135,306
Level I [Member] | U.S. Government and agencies [Member]
Total fixed income securities
Level I [Member] | Obligations of states and political subdivisions [Member]
Total fixed income securities
Level I [Member] | Corporate securities [Member]
Total fixed income securities
Level I [Member] | Residential mortgage-backed securities [Member]
Total fixed income securities
Level I [Member] | Commercial mortgage-backed securities [Member]
Total fixed income securities
Level I [Member] | Asset backed securities [Member]
Total fixed income securities
Level I [Member] | Basic materials [Member]
Total equity securities	1,066	1,285
Level I [Member] | Communications [Member]
Total equity securities	8,033	7,455
Level I [Member] | Consumer, cyclical [Member]
Total equity securities	11,047	9,929
Level I [Member] | Consumer, non-cyclical [Member]
Total equity securities	16,298	14,633
Level I [Member] | Energy [Member]
Total equity securities	2,089	1,499
Level I [Member] | Financial [Member]
Total equity securities	6,841	6,235
Level I [Member] | Industrial [Member]
Total equity securities	15,088	12,733
Level I [Member] | Technology [Member]
Total equity securities	17,809	16,145
Level I [Member] | Utility [Member]
Total equity securities	97	38
Level II [Member]
Total fixed income securities	369,738	320,410
Total equity securities
Cash equivalents
Total assets at fair value	369,738	320,410
Level II [Member] | U.S. Government and agencies [Member]
Total fixed income securities	14,757	14,383
Level II [Member] | Obligations of states and political subdivisions [Member]
Total fixed income securities	71,962	64,244
Level II [Member] | Corporate securities [Member]
Total fixed income securities	160,768	128,434
Level II [Member] | Residential mortgage-backed securities [Member]
Total fixed income securities	41,904	36,494
Level II [Member] | Commercial mortgage-backed securities [Member]
Total fixed income securities	30,819	25,655
Level II [Member] | Asset backed securities [Member]
Total fixed income securities	49,528	51,200
Level II [Member] | Basic materials [Member]
Total equity securities
Level II [Member] | Communications [Member]
Total equity securities
Level II [Member] | Consumer, cyclical [Member]
Total equity securities
Level II [Member] | Consumer, non-cyclical [Member]
Total equity securities
Level II [Member] | Energy [Member]
Total equity securities
Level II [Member] | Financial [Member]
Total equity securities
Level II [Member] | Industrial [Member]
Total equity securities
Level II [Member] | Technology [Member]
Total equity securities
Level III [Member]
Total fixed income securities
Total equity securities
Cash equivalents
Total assets at fair value
Level III [Member] | U.S. Government and agencies [Member]
Total fixed income securities
Level III [Member] | Obligations of states and political subdivisions [Member]
Total fixed income securities
Level III [Member] | Corporate securities [Member]
Total fixed income securities
Level III [Member] | Residential mortgage-backed securities [Member]
Total fixed income securities
Level III [Member] | Commercial mortgage-backed securities [Member]
Total fixed income securities
Level III [Member] | Asset backed securities [Member]
Total fixed income securities
Level III [Member] | Basic materials [Member]
Total equity securities
Level III [Member] | Communications [Member]
Total equity securities
Level III [Member] | Consumer, cyclical [Member]
Total equity securities
Level III [Member] | Consumer, non-cyclical [Member]
Total equity securities
Level III [Member] | Energy [Member]
Total equity securities
Level III [Member] | Financial [Member]
Total equity securities
Level III [Member] | Industrial [Member]
Total equity securities
Level III [Member] | Technology [Member]
Total equity securities