| Cover | Mar. 13, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 13, 2024 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-39546 |
| Entity Registrant Name | Proterra Inc |
| Entity Central Index Key | 0001820630 |
| Entity Tax Identification Number | 90-2099565 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 504 Pennsylvania Avenue |
| Entity Address, Address Line Two | PO Box 2205 |
| Entity Address, City or Town | Greer |
| Entity Address, State or Province | SC |
| Entity Address, Postal Zip Code | 29652 |
| City Area Code | 303 |
| Local Phone Number | 689-8855 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
