| Cover | Feb. 25, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 25, 2021 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 1-36132 |
| Entity Registrant Name | PLAINS GP HOLDINGS LP |
| Entity Central Index Key | 0001581990 |
| Entity Tax Identification Number | 90-1005472 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 333 Clay Street |
| Entity Address, Address Line Two | Suite 1600 |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77002 |
| City Area Code | 713 |
| Local Phone Number | 646-4100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Shares |
| Trading Symbol | PAGP |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
