Document and Entity Information - shares |
6 Months Ended | |
|---|---|---|
Jun. 30, 2018 |
Aug. 06, 2018 |
|
| Document And Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Jun. 30, 2018 | |
| Document Fiscal Year Focus | 2018 | |
| Document Fiscal Period Focus | Q2 | |
| Trading Symbol | PEGI | |
| Entity Registrant Name | Pattern Energy Group Inc. | |
| Entity Central Index Key | 0001561660 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Filer Category | Large Accelerated Filer | |
| Entity Common Stock, Shares Outstanding | 98,096,323 |