Fair Value (Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets:
Total assets	$ 114,523
Fair Value, Measurements, Recurring
Assets:
Total assets	168,937	$ 218,134
Fair Value, Measurements, Recurring | Money market funds
Assets:
Total assets	54,414	38,360
Fair Value, Measurements, Recurring | Commercial paper
Assets:
Total assets	11,935	22,978
Fair Value, Measurements, Recurring | Government and agency obligations
Assets:
Total assets	32,637	32,690
Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total assets	67,598	95,845
Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total assets	2,353	28,261
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total assets	32,637	32,690
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial paper
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government and agency obligations
Assets:
Total assets	32,637	32,690
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed securities
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Total assets	136,300	185,444
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Assets:
Total assets	54,414	38,360
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Total assets	11,935	22,978
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Government and agency obligations
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate bonds
Assets:
Total assets	67,598	95,845
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Total assets	2,353	28,261
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3)
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3) | Money market funds
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3) | Commercial paper
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3) | Government and agency obligations
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3) | Corporate bonds
Assets:
Total assets	0	0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 3) | Asset-backed securities
Assets:
Total assets	$ 0	$ 0