Supplemental Financial Statement Information (Narrative) (Details) gal in Millions	3 Months Ended
Oct. 31, 2016 gal
Maximum term of supply procurement contracts	36 months
Net procurement of fixed priced propane in gallons	93.4
Ferrellgas, L.P. [Member]
Maximum term of supply procurement contracts	36 months
Net procurement of fixed priced propane in gallons	93.4

Net Procurement Of Fixed Priced Propane In Gallons

No definition available.

Name:	fgp_NetProcurementOfFixedPricedPropaneInGallons
Namespace Prefix:	fgp_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant