| Document And Entity Information | Feb. 27, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 27, 2023 |
| Entity Registrant Name | ROCKET LAB USA, INC. |
| Entity Central Index Key | 0001819994 |
| Entity Emerging Growth Company | false |
| Securities Act File Number | 001-39560 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 98-1550340 |
| Entity Address, Address Line One | 3881 McGowen Street |
| Entity Address, City or Town | Long Beach |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90808 |
| City Area Code | 714 |
| Local Phone Number | 465-5737 |
| Entity Information, Former Legal or Registered Name | Not Applicable |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | RKLB |
| Security Exchange Name | NASDAQ |
