Acquisitions and Dispositions (Details Textual) (Details) In Millions, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended	1 Months Ended		12 Months Ended							12 Months Ended					0 Months Ended					0 Months Ended
	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Jan. 12, 2012 Heritage Propane [Member] USD ($)	Jun. 30, 2012 Heritage Propane [Member] USD ($)	Apr. 30, 2012 Heritage Propane [Member] USD ($)	Sep. 30, 2012 Heritage Propane [Member] USD ($)	Dec. 31, 2011 Heritage Propane [Member] Customer gal	Oct. 31, 2011 International Propane [Member] USD ($)	Oct. 31, 2011 International Propane [Member] EUR (€)	Jan. 12, 2012 Energy Transfer Partners, LP [Member] States	Jan. 12, 2012 Heritage Operating LP [Member]	Jan. 12, 2012 Titan Energy GP LLC [Member]	Sep. 30, 2012 Amerigas [Member] USD ($)	Sep. 30, 2011 Amerigas [Member] USD ($)	Sep. 30, 2010 Amerigas [Member] USD ($)	Sep. 30, 2011 International Propane [Member] USD ($)	Sep. 30, 2010 International Propane [Member] USD ($)	Jul. 30, 2010 Atlantic Energy [Member] USD ($) gal	Jan. 12, 2012 Amerigas Partners Senior Notes Due 2020 [Member]	Jan. 12, 2012 Amerigas Partners Senior Notes Due 2020 [Member] Heritage Propane [Member] USD ($)	Jan. 12, 2012 Amerigas Partners Senior Notes Due 2022 [Member]	Jan. 12, 2012 Amerigas Partners Senior Notes Due 2022 [Member] Heritage Propane [Member] USD ($)	Jan. 12, 2012 General Partner [Member] Heritage Propane [Member] USD ($)
Business Acquisition [Line Items]
Purchase price of the acquisition				$ 2,598.2					$ 179.0	€ 133.6
Business acquired by parent through subsidiaries for cash				1,465.6			1,472.2
Common units issued by AmeriGas Partners (in units)				29,567,362
Business Acquisition, Cost of Acquired Entity, Equity Interests Issued and Issuable				1,132.6			1,132.6
Working Capital Adjustment, Additional Cash Paid						25.5
Purchase price adjustment cash received					18.9
Number of states in which business operates (in states)											41
Annual Delivery of Propane by Acquired Subsidiary (in gallons)								500,000,000
Number of Retail Customer (in customers)								1,000,000
Percentage of Contribution by Contributor in Form of Limited Partner Interest												99.999%	99.99%
Percentage of Contribution by Contributor in Form of Membership Interest												100.00%	100.00%
Percentage of Remaining Contribution by Contributor in Form of General Partner Interest				0.001%									0.01%
Partners' Capital Account, Units, Contributed																								934,327
Partners' Capital Account, Contributions																								41.7
Long-term Debt	3,514.3	2,157.7																			550.0		1,000.0
Interest rate stated percentage																				6.75%	6.75%	7.00%	7.00%
Business Acquisition, Purchase Price Allocation, Current Assets, Cash and Cash Equivalents							60.7
Business Combination, Acquisition Related Costs							5.3
Cash consideration to acquire business	1,580.5	52.5	83.0											13.5	34.0	34.3	19.0	48.7
Ownership percentage acquired																		46.00%
Discontinued Operations and Disposal Groups [Abstract]
Proceeds from sale of investment in Atlantic Energy			66.6																49.0
Amount of gallon marine import and transhipment facility that company owns and operates (in gallons)																			20,000,000
Pre-tax gain on the sale which amount is included in other income, net			36.5
Increase in net income attributable to parent due to gain on sale			$ 17.2