SEGMENT INFORMATION: (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012 2014 Notes	Mar. 31, 2013 Lithium	Mar. 31, 2012 Lithium	Mar. 31, 2013 Surface Treatment	Mar. 31, 2012 Surface Treatment	Mar. 31, 2013 Performance Additives	Mar. 31, 2012 Performance Additives	Mar. 31, 2013 Titanium Dioxide Pigments	Mar. 31, 2012 Titanium Dioxide Pigments	Mar. 31, 2013 Advanced Ceramics	Mar. 31, 2012 Advanced Ceramics	Mar. 31, 2013 Corporate and other	Mar. 31, 2012 Corporate and other
Segment information
Income (loss) before taxes	$ 24.9	$ 120.3		$ 30.4	$ 16.0	$ 27.2	$ 22.7	$ 19.1	$ 18.5	$ (33.3)	$ 53.6	$ 29.4	$ 28.6	$ (47.9)	$ (19.1)
Interest expense, net	29.0	20.5		0.7	1.0	3.0	5.2	1.4	2.2	5.9	1.9	3.6	4.6	14.4	5.6
Depreciation and amortization	67.0	65.8		11.1	10.7	7.9	7.9	14.4	15.1	18.2	17.3	13.1	12.8	2.3	2.0
Restructuring and other severance costs	7.1	14.2		3.9	11.3	2.2	0.8	0.6	2.0	0.3		0.1			0.1
Systems/organization establishment expenses (income)	0.6	1.6		0.1		0.6			0.1	(0.1)	1.5
Acquisition and disposal costs	6.1			0.1				0.1				0.2		5.7
Loss on early extinguishment/modification of debt	17.6	9.7			2.2		3.0		0.9	17.6			0.7		2.9
Foreign exchange loss (gain) on financing activities, net	15.3	1.0		0.6	3.2	(1.9)		0.1				0.1	(0.5)	16.4	(1.7)
Other	0.6	1.8				0.5	0.1	0.1			1.3		0.1		0.3
Total Adjusted EBITDA	168.2	234.9		46.9	44.4	39.5	39.7	35.8	38.8	8.6	75.6	46.5	46.3	(9.1)	(9.9)
Redemption premiums			6.7
Write-off of deferred financing costs			$ 0.3							$ 17.6