| Cover | May 23, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 23, 2022 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 000-55610 |
| Entity Registrant Name | GREENBACKER RENEWABLE ENERGY CO LLC |
| Entity Central Index Key | 0001563922 |
| Entity Tax Identification Number | 80-0872648 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 230 Park Avenue, Suite 1560 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10169 |
| City Area Code | (646) |
| Local Phone Number | 237-7884 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | true |
