Investments (Summary Of Short-term Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Summary of Investment Holdings [Line Items]
Cost Basis	$ 118,221	$ 180,661
Unrealized Losses	(3,698)	(887)
Fair Value	114,523	179,774
Corporate bonds
Summary of Investment Holdings [Line Items]
Cost Basis	69,832	96,408
Unrealized Losses	(2,234)	(563)
Fair Value	67,598	95,845
Government and agency obligations
Summary of Investment Holdings [Line Items]
Cost Basis	33,971	32,953
Unrealized Losses	(1,334)	(263)
Fair Value	32,637	32,690
Commercial paper
Summary of Investment Holdings [Line Items]
Cost Basis	11,935	22,978
Unrealized Losses	0	0
Fair Value	11,935	22,978
Asset-backed securities
Summary of Investment Holdings [Line Items]
Cost Basis	2,483	28,322
Unrealized Losses	(130)	(61)
Fair Value	$ 2,353	$ 28,261