| Cover Page | Aug. 05, 2019 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Aug. 5, 2019 |
| Entity Registrant Name | AmeriGas Partners LP |
| Entity Central Index Key | 0000932628 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-13692 |
| Entity Tax Identification Number | 23-2787918 |
| Entity Address, Address Line One | 460 North Gulph Road |
| Entity Address, City or Town | King of Prussia |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19406 |
| City Area Code | 610 |
| Local Phone Number | 337-7000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Units representing limited partner interests |
| Trading Symbol | APU |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
