Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Net sales	$ 372.3	$ 388.3
Gross profit/(loss)	113.9	117.8
Operating income/(loss)	40.9	36.2
Operating Segments [Member] | Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	147.0	156.0
Gross profit/(loss)	51.2	55.7
Operating income/(loss)	32.1	32.9
Operating Segments [Member] | Fuel Specialties [Member] | Refinery and Performance [Member]
Segment Reporting Information [Line Items]
Net sales	108.6	117.3
Operating Segments [Member] | Fuel Specialties [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	38.4	38.7
Operating Segments [Member] | Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	113.1	118.1
Gross profit/(loss)	27.6	26.6
Operating income/(loss)	15.6	13.5
Operating Segments [Member] | Performance Chemicals [Member] | Personal Care [Member]
Segment Reporting Information [Line Items]
Net sales	63.0	61.0
Operating Segments [Member] | Performance Chemicals [Member] | Home Care [Member]
Segment Reporting Information [Line Items]
Net sales	21.6	27.0
Operating Segments [Member] | Performance Chemicals [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	28.5	30.1
Operating Segments [Member] | Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	112.2	114.2
Gross profit/(loss)	36.2	37.7
Operating income/(loss)	7.2	7.8
Operating Segments [Member] | Octane Additives [Member]
Segment Reporting Information [Line Items]
Gross profit/(loss)	(1.1)	(2.2)
Operating income/(loss)	(1.2)	(2.8)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (12.8)	$ (15.2)