Investments, Securities with Continuous Unrealized Loss Position (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) Securities	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) Securities
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	$ 18,084		$ 6,878
12 months or longer	179,579		183,695
Total	197,663		190,573
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	221		53
12 months or longer	23,672		21,638
Total	$ 23,893		$ 21,691
Number of securities in unrealized loss position | Securities	224		222
Allowance for expected credit losses on available-for-sale fixed maturities	$ 0		$ 0
Realized investment gains	0	$ 0
U.S. Treasury Securities and Obligations of U.S. Government Agencies and Authorities [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	5,161		5,194
12 months or longer	37,250		39,476
Total	42,411		44,670
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	44		37
12 months or longer	5,075		4,907
Total	5,119		4,944
Allowance for expected credit losses on available-for-sale fixed maturities	0		0
Obligations of States and Political Subdivisions [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	1,130		1,145
12 months or longer	5,985		5,936
Total	7,115		7,081
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	16		3
12 months or longer	1,372		1,421
Total	1,388		1,424
Allowance for expected credit losses on available-for-sale fixed maturities	0		0
Corporate Securities [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	11,793		539
12 months or longer	136,344		138,283
Total	148,137		138,822
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	161		13
12 months or longer	17,225		15,310
Total	17,386		15,323
Allowance for expected credit losses on available-for-sale fixed maturities	$ 0		$ 0