Fair Value Of Financial Instruments (Schedule Of Changes In Fair Value Associated With Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Asset-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 1,498	$ 2,179
Realized gains/(losses)	1,542	1,007
Redemptions	(2,006)	(1,688)
Net change	(464)	(681)
Ending Balance	1,034	1,498
Syndicated Loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	82,964	69,888
Unrealized gains/(losses)	1,673	(15)
Realized gains/(losses)	(3,252)	(2,161)
Purchases	54,335	69,881
Sales	(49,810)	(35,988)
Redemptions	(25,718)	(18,641)
Transfers out of Level 3	(1,725)
Net change	(24,497)	13,076
Ending Balance	58,467	82,964
Corporate Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	11,878	11,878
Unrealized gains/(losses)	3,687
Net change	3,687
Ending Balance	15,565	11,878
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	783	14,681
Unrealized gains/(losses)		2
Realized gains/(losses)		(232)
Redemptions	(225)	(13,668)
Net change	(225)	(13,898)
Ending Balance	558	783
Other Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	39,467	36,974
Unrealized gains/(losses)	(119)	993
Realized gains/(losses)		0
Purchases		1,500
Transfers out of Level 3	(25,000)
Net change	(25,119)	2,493
Ending Balance	$ 14,348	$ 39,467