Class Of Warrant Or Right Fair Value

No definition available.

Name:	rklb_ClassOfWarrantOrRightFairValue
Namespace Prefix:	rklb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Class of Warrant or Right, Number of Securities Called by Warrants or Rights Vested.

+ References

No definition available.

+ Details

Name:	rklb_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRightsVested
Namespace Prefix:	rklb_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase in additional paid in capital (APIC) resulting from the issuance of warrants. Includes allocation of proceeds of debt securities issued with detachable stock purchase warrants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123466302&loc=d3e4724-112606

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

+ Details

Name:	us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

Name:	us-gaap_WarrantsAndRightsOutstandingTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=rklb_RocketLabUsaIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesBPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesCPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesDPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AdditionalPaidInCapitalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Dec. 23, 2020	Dec. 31, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Warrants term	5 years
Fair value of warrants	$ 2,433		$ 6,514
Rocket Lab USA, Inc.
Class of Warrant or Right [Line Items]
Warrants issued				13,432
Warrants exercise price				$ 11.62
Estimated fair value of warrants	496	$ 769
Fair value of warrants	2,433
Rocket Lab USA, Inc. \| Series B Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Warrants issued						33,774
Warrants exercise price						$ 1.80
Warrants term						10 years
Fair value of warrants	$ 1,466	$ 515	$ 2,863
Rocket Lab USA, Inc. \| Series C Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Warrants issued					13,090
Warrants exercise price					$ 2.25
Warrants to purchase vested	9,600	7,636
Rocket Lab USA, Inc. \| Series D Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Warrants issued					77,198
Warrants exercise price					$ 19.05
Warrants to purchase vested	56,612	45,032
Rocket Lab USA, Inc. \| Common Stock [Member]
Class of Warrant or Right [Line Items]
Warrants issued	13,432			13,432	51,184
Warrants exercise price	$ 11.62			$ 11.62	$ 0.82
Warrants term				10 years	10 years
Fair value of warrants					$ 23
Rocket Lab USA, Inc. \| Additional Paid-in Capital
Class of Warrant or Right [Line Items]
Estimated fair value of warrants	$ 496