Properties, including oil and gas properties, net Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Property, Plant and Equipment [Line Items]
Oil And Gas Property Full Cost Method Cost Not Amortized	$ 20.2	$ 36.4
Proved developed and undeveloped oil and natural gas properties	493.9	546.0
Less: Accumulated depletion	(68.4)	(30.1)
Total oil and natural gas properties, net	445.7	552.3
Land, buildings and improvements	815.9	726.0
Less: Accumulated depreciation	353.0	285.0
Total other properties, net	462.9	441.0
Total properties, including oil and natural gas properties, net	908.6	993.3
Impairment of oil and natural gas properties	81.0	54.3	0
Land, buildings and improvements
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	166.9	169.8
Gas gathering assets
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	21.1	21.1
Machinery, equipment and other
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	496.3	420.6
Assets Held under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	99.3	67.7
Construction in progress
Property, Plant and Equipment [Line Items]
Land, buildings and improvements	32.3	46.8
Compass
Property, Plant and Equipment [Line Items]
Impairment of oil and natural gas properties	81.0	54.3
Unproved Oil and Natural Gas Properties and Development Costs Not Being Amortized | Compass
Property, Plant and Equipment [Line Items]
Capitalized Costs, Unproved Properties	$ 20.2