Pension Plans and Other Postretirement Benefits Domestic and Foreign Pension and Postretirement Defined Benefit Plans (Footnote) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Gain recognized related to termination of plan	$ 0	$ 2,594	[1]

[1] We assumed responsibility for one domestic OPEB plan in connection with the acquisition of Rockwood which covered a small number of active employees and retirees. This plan was terminated in the first quarter of 2015 and provisions were made for the affected employees and retirees to receive benefits under an existing plan. A gain of $2.6 million was recognized in the first quarter of 2015 related to the termination of this plan.