Pension Plans and Other Postretirement Benefits Pension and Postretirement Plan Contributions (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension Contributions	$ 4.5	$ 1.2	$ 9.1	$ 2.3
Other Postretirement Benefits Payments	$ 0.5	$ 1.0	1.9	$ 2.4
Rockwood Holdings, Inc. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Expected Contributions to Rockwood Pension Plans for the Remainder of 2015			$ 2.2