Investments (Schedule of Fixed Maturities) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Marketable Securities [Abstract]
Amortized Cost, Due in one year or less	$ 30,870
Amortized Cost, Due after one year through five years	443,417
Amortized Cost, Due after five years through ten years	348,824
Amortized Cost, Due after ten years through twenty years	55,342
Amortized Cost, Due after twenty years	39,610
Amortized Cost, No maturity	5,000
Amortized Cost	923,063	$ 679,921
Estimated Fair Value, Due in one year or less	30,505
Estimated Fair Value, Due after one year through five years	440,196
Estimated Fair Value, Due after five years through ten years	333,739
Estimated Fair Value, Due after ten years through twenty years	51,367
Estimated Fair Value, Due after twenty years	34,586
Estimated Fair Value, No maturity	4,078
Estimated Fair Value	$ 894,471	$ 683,296