Derivatives (Derivatives Outstanding) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014
Derivative [Line Items]
Total mark to market derivatives	$ (0.2)
Commodity
Derivative [Line Items]
Total mark to market derivatives	(0.2)
Short [Member] | Natural Gas Liquids [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount	61,300,000
Total mark to market derivatives	0.7
Short [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount	2,200,000
Total mark to market derivatives	0.1
Long [Member] | Natural Gas Liquids [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount	47,900,000
Total mark to market derivatives	(0.9)
Long [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount	400,000
Total mark to market derivatives	$ (0.1)