Fair Value Measurements - Recurring Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Marketable securities	$ 452,875	$ 149,903
Other liabilities
Redeemable convertible preferred stock warrant liabilities	0	2,517
Fair Value, Measurements, Recurring
Assets
Total assets	1,666,418	353,495
Other liabilities
Total liabilities		2,517
Fair Value, Measurements, Recurring \| Redeemable convertible preferred stock warrants
Other liabilities
Redeemable convertible preferred stock warrant liabilities		2,517
Fair Value, Measurements, Recurring \| Money market funds
Assets
Money market funds	1,213,543	203,592
Fair Value, Measurements, Recurring \| U.S. government securities
Assets
Marketable securities	418,284	125,864
Fair Value, Measurements, Recurring \| Commercial paper
Assets
Marketable securities	13,878	4,991
Fair Value, Measurements, Recurring \| Asset-backed securities
Assets
Marketable securities	2,002	4,315
Fair Value, Measurements, Recurring \| Corporate debt securities
Assets
Marketable securities	18,711	14,733
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1
Assets
Total assets	1,631,827	329,456
Other liabilities
Total liabilities		0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| Redeemable convertible preferred stock warrants
Other liabilities
Redeemable convertible preferred stock warrant liabilities		0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| Money market funds
Assets
Money market funds	1,213,543	203,592
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| U.S. government securities
Assets
Marketable securities	418,284	125,864
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| Commercial paper
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| Asset-backed securities
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1 \| Corporate debt securities
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2
Assets
Total assets	34,591	24,039
Other liabilities
Total liabilities		0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Redeemable convertible preferred stock warrants
Other liabilities
Redeemable convertible preferred stock warrant liabilities		0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Money market funds
Assets
Money market funds	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| U.S. government securities
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Commercial paper
Assets
Marketable securities	13,878	4,991
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Asset-backed securities
Assets
Marketable securities	2,002	4,315
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Corporate debt securities
Assets
Marketable securities	18,711	14,733
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3
Assets
Total assets	0	0
Other liabilities
Total liabilities		2,517
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Redeemable convertible preferred stock warrants
Other liabilities
Redeemable convertible preferred stock warrant liabilities		2,517
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Money market funds
Assets
Money market funds	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| U.S. government securities
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Commercial paper
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Asset-backed securities
Assets
Marketable securities	0	0
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Corporate debt securities
Assets
Marketable securities	$ 0	$ 0

No definition available.

Name:	us-gaap_AssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CashEquivalentsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of financial and nonfinancial obligations.

+ References

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

No definition available.

+ Details

Name:	us-gaap_WarrantsAndRightsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: