Summary of Significant Accounting Policies - Schedule of Income Per Limited Partner Unit (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Accounting Policies [Abstract]
Net income attributable to AmeriGas Partners, L.P.	$ 245,908	$ 326,055	$ 326,881	$ 286,484
Adjust for general partner share and theoretical distributions of net income attributable to AmeriGas Partners, L.P. to the general partner in accordance with the two-class method for MLPs	(84,240)	(123,918)	(86,865)	(66,894)
Common Unitholders’ interest in net income attributable to AmeriGas Partners, L.P. under the two-class method for MLPs	$ 161,668	$ 202,137	$ 240,016	$ 219,590
Weighted average Common Units outstanding—basic (thousands) (in units)	92,954	92,914	92,939	92,905
Potentially dilutive Common Units (thousands) (in units)	66	49	75	65
Weighted average Common Units outstanding—diluted (thousands) (in units)	93,020	92,963	93,014	92,970