The Company and Significant Accounting Policies - Summary of Amortized Cost and Unrealized (Gains) Losses of Available for Sale Securities (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Certificates of Deposit
Amortized Cost
Due within a year	$ 2,796
Total	2,796
Unrealized gains (losses)
Due within a year	34
Total	34
Corporate Bonds
Amortized Cost
Due within a year	49,898
Total	49,898
Unrealized gains (losses)
Due within a year	480
Total	$ 480