Fair Value Of Financial Instruments (Schedule of Changes in Fair Value Associated with Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2025
Asset-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 10,165	$ 1,034
Realized gains/(losses)	(942)	(942)
Purchases		9,131
Sales	(8,189)	(8,189)
Net change	(9,131)	0
Ending Balance	1,034	1,034
Syndicated Loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	43,359	58,467
Unrealized gains/(losses)	99	151
Purchases	1,170	10,070
Redemptions	(4,818)	(28,878)
Net change	(3,549)	(18,657)
Ending Balance	39,810	39,810
Corporate Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	15,497	15,565
Realized gains/(losses)		(404)
Purchases	1,577	1,913
Net change	1,577	1,509
Ending Balance	17,074	17,074
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	552	558
Unrealized gains/(losses)	2	(4)
Net change	2	(4)
Ending Balance	554	554
Other Investment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	13,640	14,348
Unrealized gains/(losses)		47
Realized gains/(losses)		(755)
Net change	0	(708)
Ending Balance	$ 13,640	$ 13,640