Investments In Securities and Fair Value (Schedule Of Gross Realized and Unrealized Gains And Losses On Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Marketable Security, Gain (Loss) [Abstract]
Corporate debt securities, realized gains	$ 2	$ 0	$ 5	$ 0
Equity securities, realized gains	1,599	1,906	4,156	4,713
Debit and equity securities, realized gains	1,601	1,906	4,161	4,713
Equity securities, realized losses	(326)	(55)	(613)	(217)
Write-down of securities	0	(21)	0	(74)
Debt and equity securities, realized loss	(326)	(76)	(613)	(291)
Debt and equity securities, net realized gain (loss)	1,275	1,830	3,548	4,422
Gross gains on other investments	0	1	1	1
Write-down of other assets	(144)	0	(419)	0
Net gains (losses) on other investments	(144)	1	(418)	1
Net realized investment gains (losses)	1,131	1,831	3,130	4,423
Unrealized gain (loss) on investments	973	(589)	(2,205)	(759)
Net investment gains	$ (2,104)	$ (1,242)	$ (925)	$ (3,664)