Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring $ in Thousands	Dec. 31, 2021 USD ($)
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Money market instruments	$ 537
Corporate bonds	0
Treasury bills
Asset-backed securities	0
Agency bonds	0
Sovereign bonds	0
Municipal bonds	0
Economic hedge forward contracts	0
Liabilities:
Economic hedge forward contracts	0
Significant Other Observable Inputs (Level 2)
Assets:
Money market instruments	0
Corporate bonds	554,306
Treasury bills	58,665
Asset-backed securities	81,595
Agency bonds	18,879
Sovereign bonds	2,119
Municipal bonds	5,639
Economic hedge forward contracts	39
Liabilities:
Economic hedge forward contracts	230
Unobservable Inputs (Level 3)
Assets:
Money market instruments	0
Corporate bonds	0
Treasury bills
Asset-backed securities	0
Agency bonds	0
Sovereign bonds	0
Municipal bonds
Economic hedge forward contracts	0
Liabilities:
Economic hedge forward contracts	$ 0