Segment Reporting and Geographical Area Data - Segment Reporting (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 1,513.3	$ 1,476.9	$ 1,306.8
Gross profit	466.2	435.0	403.3
Restructuring charge	0.0	7.1	0.0
Loss on disposal of subsidiary	0.0	0.0	(0.9)
Foreign exchange loss on liquidation of subsidiary	0.0	0.0	(1.8)
Operating income	149.9	133.5	125.0
Identifiable assets at year end	1,468.8	1,473.4	1,410.2
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	583.7	574.5	523.8
Gross profit	204.5	195.0	188.2
Operating income	116.6	116.3	107.7
Identifiable assets at year end	499.7	470.5	437.0
Operating Segments [Member] \| Fuel Specialties [Member] \| Refinery and Performance [Member]
Segment Reporting Information [Line Items]
Net sales	427.9	432.1	397.0
Operating Segments [Member] \| Fuel Specialties [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	155.8	142.4	126.8
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	428.7	468.1	419.5
Gross profit	100.1	97.5	75.8
Operating income	48.7	44.7	32.6
Identifiable assets at year end	383.3	463.9	480.8
Operating Segments [Member] \| Performance Chemicals [Member] \| Personal Care [Member]
Segment Reporting Information [Line Items]
Net sales	228.0	241.4	206.5
Operating Segments [Member] \| Performance Chemicals [Member] \| Home Care [Member]
Segment Reporting Information [Line Items]
Net sales	93.4	109.1	103.4
Operating Segments [Member] \| Performance Chemicals [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	107.3	117.6	109.6
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	479.9	400.6	304.4
Gross profit	159.9	130.4	109.3
Operating income	39.7	22.1	9.5
Identifiable assets at year end	316.8	296.1	256.6
Operating Segments [Member] \| Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	21.0	33.7	59.1
Gross profit	1.7	12.1	30.0
Operating income	(0.7)	9.9	26.7
Identifiable assets at year end	24.2	39.6	41.7
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	(54.4)	(52.4)	(48.8)
Restructuring charge	0.0	(7.1)	0.0
Identifiable assets at year end	244.8	203.3	194.1
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Loss on disposal of subsidiary	$ 0.0	$ 0.0	$ (0.9)

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