| Document and Entity Information | Aug. 21, 2019 |
| Cover [Abstract] | |
| Entity Registrant Name | AMERIGAS PARTNERS LP |
| Amendment Flag | false |
| Entity Central Index Key | 0000932628 |
| Document Type | 8-K |
| Document Period End Date | Aug. 21, 2019 |
| Entity Incorporation State 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 | 337-1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Units representing limited partner interests |
| Trading Symbol | APU |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
