| Cover | Nov. 16, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 16, 2023 |
| 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 | 1815 Rollins Road |
| Entity Address, City or Town | Burlingame |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94010 |
| City Area Code | 864 |
| Local Phone Number | 438-0000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
