Investments in Securities and Fair Value Investments in Securities (Schedule of Unrealized Losses on Investments) (Details) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	52	51
Government obligations
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 1,488	$ 4,322
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2)	(7)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	1,488	4,322
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2)	(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	5,925	3,221
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(23)	(36)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	101	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1)	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	6,026	3,221
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(24)	(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	7,124	12,568
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(16)	(216)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	3,085	1,100
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(50)	(3)
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	10,209	13,668
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(66)	(219)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	6,052	6,498
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(29)	(68)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	296	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(4)	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	6,348	6,498
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(33)	(68)
Total fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	20,589	26,609
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(70)	(327)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	3,482	1,100
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(55)	(3)
Debt Securities, Available-for-sale, Unrealized Loss Position, Total	24,071	27,709
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (125)	$ (330)