Commitments and Contingencies Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	16 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Oct. 31, 2014 Subsequent Event [Member]	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Maximum [Member]
Loss Contingencies [Line Items]
Environmental Remediation Expense	$ 14.0	$ 128.0
Environmental Remediation Expense Incurred to Date		112.5
Gross Proceeds from Insurance Settlement, Operating Activities			25.0
Net Proceeds from Insurance Settlement, Operating Activities			$ 23.9
Estimated Percentage of Environmental Remediation Expense Estimate to be Recovered Through Insurance Proceeds				33.33333%	66.66667%
Insurance reimbursement received as a percentage of the total cost estimate related to the Delhi Field release and remediation			20.00%