Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	$ 254,855	$ 398,119
Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	65,706	7,402
U.S. Government bonds and notes
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	62,622	102,812
Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	126,527	287,905
Recurring basis
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	254,855	398,119
Recurring basis | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	65,706	7,402
Recurring basis | U.S. Government bonds and notes
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	62,622	102,812
Recurring basis | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	126,527	287,905
Recurring basis | Quoted market prices in active markets (Level 1)
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	65,706	7,402
Recurring basis | Quoted market prices in active markets (Level 1) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	65,706	7,402
Recurring basis | Quoted market prices in active markets (Level 1) | U.S. Government bonds and notes
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Quoted market prices in active markets (Level 1) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Significant other observable inputs (Level 2)
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	189,149	390,717
Recurring basis | Significant other observable inputs (Level 2) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Significant other observable inputs (Level 2) | U.S. Government bonds and notes
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	62,622	102,812
Recurring basis | Significant other observable inputs (Level 2) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	126,527	287,905
Recurring basis | Significant unobservable inputs (Level 3)
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Significant unobservable inputs (Level 3) | Money market funds
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Significant unobservable inputs (Level 3) | U.S. Government bonds and notes
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	0	0
Recurring basis | Significant unobservable inputs (Level 3) | Corporate notes, bonds and commercial paper
Financial assets subject to fair value measurements and the necessary disclosures
Fair value, available-for-sale securities	$ 0	$ 0