Investments in Securities and Fair Value Investments in Securities (Schedule of Unrealized Losses on Investments) (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	51	9
Government obligations
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 4,322
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(7)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	4,322
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(7)
General obligations of U.S. states, territories and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	3,221
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(36)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	3,221
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(36)
Special revenue issuer obligations of U.S. states, territories and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	12,568	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(216)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,100	1,102
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(3)	(2)
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	13,668	1,102
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(219)	(2)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	6,498	8,493
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(68)	(13)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	6,203
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	(35)
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	6,498	14,696
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(68)	(48)
Total fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	26,609	8,493
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(327)	(13)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,100	7,305
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(3)	(37)
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	27,709	15,798
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (330)	$ (50)