Contingencies and Commitments (Details) - USD ($)	3 Months Ended
Sep. 30, 2017	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies	$ 0
Environmental remediation liability	$ 16,100,000	$ 16,100,000

Undiscounted amount of the accrual for environmental loss contingencies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.Y.Q1)
-URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

Name:	us-gaap_AccrualForEnvironmentalLossContingenciesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant