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Balance Sheet Components - Summary of Amortized Cost, Gross Unrealized Holding Gains or Losses, and Fair Value of Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 259,534	$ 8,272
Gross Unrealized Holding Gains	146	119
Gross Unrealized Holding Losses	(71)	(3)
Fair Value	259,609	8,388
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	104,499
Gross Unrealized Holding Gains	27
Gross Unrealized Holding Losses	(43)
Fair Value	104,483
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	69,400
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses	0
Fair Value	69,400
U.S. government bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	46,589
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses	(21)
Fair Value	46,568
Agency bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	14,288
Gross Unrealized Holding Gains	2
Gross Unrealized Holding Losses	(6)
Fair Value	14,284
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,489
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	0
Fair Value	12,490
Foreign government bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,151
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	(1)
Fair Value	12,151
Bond and mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		8,147
Gross Unrealized Holding Gains		0
Gross Unrealized Holding Losses		(3)
Fair Value		8,144
Equity investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	118	125
Gross Unrealized Holding Gains	115	119
Gross Unrealized Holding Losses	0	0
Fair Value	$ 233	$ 244

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563

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