Commitments and Contingencies (Details) - USD ($)	1 Months Ended	4 Months Ended	25 Months Ended
	Oct. 31, 2014	Jun. 30, 2015	Jun. 30, 2015
Loss Contingencies [Line Items]
Environmental remediation expense			$ 130,800,000
Gross proceeds from insurance settlement, operating activities	$ 25,000,000.0
Minimum
Loss Contingencies [Line Items]
Estimated percentage of environmental remediation expense estimate to be recovered through insurance proceeds		33.33333%	33.33333%
Loss Contingency, Damages Sought, Value		$ 200,000,000
Maximum
Loss Contingencies [Line Items]
Estimated percentage of environmental remediation expense estimate to be recovered through insurance proceeds		66.66667%	66.66667%