Supplementary Financial Statement Information (Details6) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Ashland Works Hot End [Member]
Restructuring Cost and Reserve [Line Items]
Costs for Temporarily Idled Operations	$ 5.0	$ 5.2	$ 10.4	$ 10.8

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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