Partnership Organization And Formation (Details)	12 Months Ended
	Jul. 31, 2017 USD ($) employee state subsidiary shares	Jul. 31, 2016 shares
Partnership formation date	Apr. 19, 1994
Limited partner interest	99.00%
General partner ownership interest	1.00%
Number Of Entity Subsidiaries | subsidiary	2
Equity interest in subsidiary	100.00%
Number of States in which Entity Operates | state	50
Number of employees | employee	0
Ferrellgas Partners Finance Corp. [Member]
Common stock shares outstanding	1,000	1,000
Corporation formation date	Mar. 28, 1996
Corporation formation proceeds from partnership | $	$ 1,000
Corporation formation shares granted to partnership	1,000
Number of employees | employee	0
Ferrellgas, L.P. [Member]
Partnership formation date	Apr. 22, 1994
Limited partner interest	99.00%
General partner ownership interest	1.00%
Equity interest in subsidiary	100.00%
Number of States in which Entity Operates | state	50
Number of employees | employee	0
Ferrellgas Finance Corp. [Member]
Common stock shares outstanding	1,000	1,000
Corporation formation date	Jan. 16, 2003
Corporation formation proceeds from partnership | $	$ 1,000
Corporation formation shares granted to partnership	1,000
Number of employees | employee	0
Ferrell Companies [Member]
Common stock shares outstanding	22,800,000
Operating Partnership [Member]
General partner ownership interest	1.00%
Ferrellgas [Member]
General partner ownership interest	2.00%