Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 388.3	$ 360.7
Gross profit	117.8	104.5
Operating income/(loss)	36.2	28.9
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	156.0	143.4
Gross profit	55.7	48.5
Operating income/(loss)	32.9	28.2
Operating Segments [Member] \| Fuel Specialties [Member] \| Refinery and Performance [Member]
Segment Reporting Information [Line Items]
Net sales	117.3	111.0
Operating Segments [Member] \| Fuel Specialties [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	38.7	32.4
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	118.1	124.0
Gross profit	26.6	25.4
Operating income/(loss)	13.5	12.1
Operating Segments [Member] \| Performance Chemicals [Member] \| Personal Care [Member]
Segment Reporting Information [Line Items]
Net sales	61.0	60.5
Operating Segments [Member] \| Performance Chemicals [Member] \| Home Care [Member]
Segment Reporting Information [Line Items]
Net sales	27.0	29.7
Operating Segments [Member] \| Performance Chemicals [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	30.1	33.8
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	114.2	92.9
Gross profit	37.7	31.4
Operating income/(loss)	7.8	3.0
Operating Segments [Member] \| Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	0.0	0.4
Gross profit	(2.2)	(0.8)
Operating income/(loss)	(2.8)	(1.4)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (15.2)	$ (13.0)

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+ References

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