Other Operating Income (Expense) - Additional Information (Details) $ in Millions	3 Months Ended
Jun. 30, 2018 USD ($)
Other Operating Income (Expense)
Other Operating Income (Expense) [Line Items]
Environmental insurance recovery write-down	$ 7.3

Amount of any recovery from third parties that is credited to environmental remediation costs.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859

Name:	us-gaap_EnvironmentalCostsRecognizedRecoveryCreditedToExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration