Fair Value Measurement, Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	$ 572,357	$ 618,092
Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	572,357	618,092
Liabilities Recorded at Fair Value [Abstract]
Liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	87,182	113,815
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	485,175	504,277
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Non-recurring [Member]
Assets Recorded at Fair Value on a Non-recurring Basis [Abstract]
Assets at fair value	0	0
Liabilities Recorded at Fair Value [Abstract]
Liabilities	0	0
U.S. Treasury Securities [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	87,182	113,815
U.S. Treasury Securities [Member] | Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	87,182	113,815
U.S. Treasury Securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	87,182	113,815
U.S. Treasury Securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
U.S. Treasury Securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Securities of U.S. Government Agencies and Corporations [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	115,079	118,911
Securities of U.S. Government Agencies and Corporations [Member] | Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	115,079	118,911
Securities of U.S. Government Agencies and Corporations [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Securities of U.S. Government Agencies and Corporations [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	115,079	118,911
Securities of U.S. Government Agencies and Corporations [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Obligations of States and Political Subdivisions [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	51,677	53,326
Obligations of States and Political Subdivisions [Member] | Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	51,677	53,326
Obligations of States and Political Subdivisions [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Obligations of States and Political Subdivisions [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	51,677	53,326
Obligations of States and Political Subdivisions [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Collateralized Mortgage Obligations [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	90,947	95,350
Collateralized Mortgage Obligations [Member] | Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	90,947	95,350
Collateralized Mortgage Obligations [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Collateralized Mortgage Obligations [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	90,947	95,350
Collateralized Mortgage Obligations [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Mortgage-backed Securities [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	227,472	236,690
Mortgage-backed Securities [Member] | Recurring [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	227,472	236,690
Mortgage-backed Securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	0	0
Mortgage-backed Securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	227,472	236,690
Mortgage-backed Securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets Recorded at Fair Value on a Recurring Basis [Abstract]
Total investments at fair value	$ 0	$ 0