Segment Information Summarized Financial Information by Reportable Segments (Footnote) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jan. 12, 2015
Research and Development Expense
Segment Reporting Information [Line Items]
Write-off of fixed assets	$ 1.4		$ 1.4
Other Income
Segment Reporting Information [Line Items]
Net gain on sale of properties	$ 0.9		$ 0.9
Rockwood Holdings, Inc.
Segment Reporting Information [Line Items]
Inventory markup					$ 103.4
Utilization of inventory markup		$ 16.8		$ 102.3
Rockwood Holdings, Inc. | Cost of Sales
Segment Reporting Information [Line Items]
Utilization of inventory markup		7.7		55.4
Rockwood Holdings, Inc. | Equity in Net Income of Unconsolidated Investments
Segment Reporting Information [Line Items]
Utilization of inventory markup		$ 9.1		$ 26.9