Investments In Securities (Schedule Of Unrealized Losses On Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Government obligations
Debt Securities, Available-for-sale [Line Items]
Total temporarily impaired securities, Less than 12 Months, Fair Value	$ 1,014	$ 1,042
Total temporarily impaired securities, Less than 12 Months, Unrealized Losses	(14)	(1)
Total temporarily impaired securities, 12 Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Total temporarily impaired securities, Total Fair Value	1,014	1,042
Total temporarily impaired securities, Unrealized Losses	(14)	(1)
General Obligations Us States And Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total temporarily impaired securities, Less than 12 Months, Fair Value	9,152	4,560
Total temporarily impaired securities, Less than 12 Months, Unrealized Losses	(146)	(27)
Total temporarily impaired securities, 12 Months or Longer, Fair Value	3,370	3,535
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(158)	(23)
Total temporarily impaired securities, Total Fair Value	12,522	8,095
Total temporarily impaired securities, Unrealized Losses	(304)	(50)
Issuer Obligations Us States And Political Subdivisions Debt Securities Special Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total temporarily impaired securities, Less than 12 Months, Fair Value	22,523	13,551
Total temporarily impaired securities, Less than 12 Months, Unrealized Losses	(290)	(61)
Total temporarily impaired securities, 12 Months or Longer, Fair Value	6,019	4,023
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(292)	(104)
Total temporarily impaired securities, Total Fair Value	28,542	17,574
Total temporarily impaired securities, Unrealized Losses	(582)	(165)
Corporate Debt Securities
Debt Securities, Available-for-sale [Line Items]
Total temporarily impaired securities, Less than 12 Months, Fair Value	10,194	3,744
Total temporarily impaired securities, Less than 12 Months, Unrealized Losses	(78)	(7)
Total temporarily impaired securities, 12 Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Total temporarily impaired securities, Total Fair Value	10,194	3,744
Total temporarily impaired securities, Unrealized Losses	(78)	(7)
Total Fixed Maturity Securities
Debt Securities, Available-for-sale [Line Items]
Total temporarily impaired securities, Less than 12 Months, Fair Value	42,883	22,897
Total temporarily impaired securities, Less than 12 Months, Unrealized Losses	(528)	(96)
Total temporarily impaired securities, 12 Months or Longer, Fair Value	9,389	7,558
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(450)	(127)
Total temporarily impaired securities, Total Fair Value	52,272	30,455
Total temporarily impaired securities, Unrealized Losses	$ (978)	$ (223)