Operating Segment Information - Segment Info and Reconciliation (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Operating segment information
Number of Reportable Segments | segment									2
Net Sales
Revenues	$ 504.5	$ 470.5	$ 513.6	$ 469.5	$ 520.0	$ 494.9	$ 485.7	$ 431.5	$ 1,958.1	$ 1,932.1	$ 1,716.5
Adjusted EBIT
Certain Pension Costs									(18.4)	(15.9)	(13.0)
Adjusted EBIT									473.2	456.7	414.0
Depreciation, Depletion and Amortization [Abstract]
Depreciation and amortization									100.3	100.8	111.5
Payments to Acquire Productive Assets [Abstract]
Capital Expenditures									194.1	216.3	125.2
Assets
Total Assets	3,932.6				3,565.3				3,932.6	3,565.3	2,907.0
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Adjusted EBIT									473.2	456.7	414.0
Costs related to legacy matters									(103.5)	(82.3)	(33.1)
Pension MTM adjustment and other related costs, net									(85.9)	15.2	(51.1)
Restructuring and repositioning expenses									(13.7)	(46.4)	(26.7)
Adjusted EBIT Benefit Plan Adjustment									(5.0)	0.0	0.0
Third-party acquisition-related costs									(3.6)	(7.3)	(2.9)
Adjusted EBIT inventory write-off									(3.6)	0.0	0.0
Amortization of Acquired Inventory Fair Value Adjustment									0.0	(6.9)	0.0
Loss on early extinguishment of debt									0.0	(4.8)	0.0
Accounts receivable reserve-Venezuela									0.0	0.0	(10.0)
Interest expense, net									(74.8)	(78.5)	(78.5)
Net Income (Loss) Attributable to Noncontrolling Interest									0.4	(0.8)	(0.8)
Income (loss) before income taxes									$ 183.5	244.9	210.9
Catalysts Technologies
Operating segment information
Number of operating segments | segment									2
Net Sales
Revenues									$ 1,496.7	1,463.5	1,276.5
Adjusted EBIT
Operating income (loss)									466.5	440.5	395.4
Depreciation, Depletion and Amortization [Abstract]
Depreciation and amortization									81.9	81.7	87.1
Payments to Acquire Productive Assets [Abstract]
Capital Expenditures									114.6	150.3	100.9
Assets
Total Assets	2,556.1				2,326.6				2,556.1	2,326.6	1,757.1
Materials Technologies
Net Sales
Revenues									461.4	468.6	440.0
Adjusted EBIT
Operating income (loss)									97.8	105.6	100.6
Depreciation, Depletion and Amortization [Abstract]
Depreciation and amortization									14.2	15.5	19.6
Payments to Acquire Productive Assets [Abstract]
Capital Expenditures									68.8	56.1	20.9
Assets
Total Assets	430.3				375.9				430.3	375.9	326.8
Corporate, Non-Segment [Member]
Adjusted EBIT
Operating income (loss)									(72.7)	(73.5)	(69.0)
Depreciation, Depletion and Amortization [Abstract]
Depreciation and amortization									4.2	3.6	4.8
Payments to Acquire Productive Assets [Abstract]
Capital Expenditures									10.7	9.9	3.4
Corporate, Non-Segment [Member]
Assets
Total Assets	$ 946.2				$ 862.8				$ 946.2	$ 862.8	$ 823.1