Acquisitions Acquisitions - Allocation of Purchase Price (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Jan. 12, 2012 Heritage Propane		Jan. 12, 2012 Heritage Propane Customer Relationships	Jan. 12, 2012 Heritage Propane Trademarks and Trade Names
Business Acquisition
Business Acquisition, Goodwill, Expected Tax Deductible Amount, Period of Amortization	15 years
Assets acquired:
Current assets				$ 301.4
Property, plant & equipment				890.2
Customer relationships						418.9
Trademarks and tradenames							91.1	[1]
Goodwill	2,833.4	2,873.7	2,818.3	1,217.7	[1],[2]
Other assets				9.9
Total assets acquired				2,929.2
Liabilities assumed:
Current liabilities				(238.1)
Long-term debt				(62.9)
Other noncurrent liabilities				(23.4)
Total liabilities assumed				(324.4)
Total				$ 2,604.8

[1] During Fiscal 2013, the Partnership made correcting adjustments to trademarks and tradenames and goodwill which are not reflected in the table above (see Note 12).

[2] Goodwill associated with the Heritage Acquisition principally results from synergies expected from combining the operations and from assembled workforce. The tax effects of such goodwill will be realized over a 15-year period.