Cash, Cash Equivalents, Restricted Cash And Investments - Summary of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value (Detail) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Fair Value	$ 287,638,000
Less than 12 Months, Gross Unrealized Losses	(1,286,000)
12 Months or Longer, Fair value	148,779,000	$ 0
12 Months or Longer, Gross Unrealized Losses	(3,511,000)
Total, Fair value	436,417,000
Total, Gross Unrealized Loses	(4,797,000)
Commercial Paper [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Fair Value	39,980,000
Less than 12 Months, Gross Unrealized Losses	(50,000)
12 Months or Longer, Fair value	0
12 Months or Longer, Gross Unrealized Losses	0
Total, Fair value	39,980,000
Total, Gross Unrealized Loses	(50,000)
Corporate Notes and Bonds [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Fair Value	59,132,000
Less than 12 Months, Gross Unrealized Losses	(544,000)
12 Months or Longer, Fair value	134,711,000
12 Months or Longer, Gross Unrealized Losses	(3,108,000)
Total, Fair value	193,843,000
Total, Gross Unrealized Loses	(3,652,000)
Municipal Bonds [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Fair Value	0
Less than 12 Months, Gross Unrealized Losses	0
12 Months or Longer, Fair value	4,872,000
12 Months or Longer, Gross Unrealized Losses	(105,000)
Total, Fair value	4,872,000
Total, Gross Unrealized Loses	(105,000)
US government and agency
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Fair Value	188,526,000
Less than 12 Months, Gross Unrealized Losses	(692,000)
12 Months or Longer, Fair value	9,196,000
12 Months or Longer, Gross Unrealized Losses	(298,000)
Total, Fair value	197,722,000
Total, Gross Unrealized Loses	$ (990,000)