Pension Plans and Other Postretirement Benefits Domestic and Foreign Pension and Postretirement Defined Benefit Plans (Footnote) (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014		Jun. 30, 2015		Jun. 30, 2014		Jan. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Net curtailment gain				$ 800
United States Pension Plan of US Entity
Defined Benefit Plan Disclosure [Line Items]
Discount rate										4.97%	5.14%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss	$ (51)		$ 0	$ 15,400	[1]	$ (51)		$ 15,432	[1]
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net curtailment gain	$ 0		$ 0			$ 2,594	[2]	$ 0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments		$ 2,594

[1] In connection with a realignment of our operating segments effective January 1, 2014, in the fourth quarter of 2013 we initiated a workforce reduction plan which resulted in a reduction of approximately 230 employees worldwide. This workforce reduction triggered a net curtailment gain of approximately $0.8 million in the first quarter of 2014 for our U.S. defined benefit plan which covers non-represented employees and our supplemental executive retirement plan (“SERP”). In connection with the curtailment, we were required to remeasure the related assets and obligations for these two plans. As of the January 31, 2014 remeasurement date, the weighted-average discount rate for all of our domestic pension plans was 4.97% compared to 5.14% at December 31, 2013. Taking into account the discount rate reduction and actual return on plan assets through January 31, 2014, we recorded a mark-to-market actuarial loss (net of the curtailment gain) of $15.4 million in the first quarter of 2014 related to these two plans.

[2] 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.