Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 360.7	$ 294.3
Gross profit/(loss)	104.5	90.9
Foreign exchange loss on liquidation of subsidiary	0.0	(1.8)
Operating income/(loss)	28.9	25.3
Operating Segments [Member] | Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	143.4	126.4
Gross profit/(loss)	48.5	46.1
Operating income/(loss)	28.2	27.0
Operating Segments [Member] | Fuel Specialties [Member] | Refinery and Performance [Member]
Segment Reporting Information [Line Items]
Net sales	111.0	100.4
Operating Segments [Member] | Fuel Specialties [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	32.4	26.0
Operating Segments [Member] | Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	124.0	94.5
Gross profit/(loss)	25.4	16.7
Operating income/(loss)	12.1	6.0
Operating Segments [Member] | Performance Chemicals [Member] | Personal Care [Member]
Segment Reporting Information [Line Items]
Net sales	57.8	47.5
Operating Segments [Member] | Performance Chemicals [Member] | Home Care [Member]
Segment Reporting Information [Line Items]
Net sales	34.2	26.9
Operating Segments [Member] | Performance Chemicals [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	32.0	20.1
Operating Segments [Member] | Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	92.9	66.5
Gross profit/(loss)	31.4	25.4
Operating income/(loss)	3.0	3.0
Operating Segments [Member] | Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	0.4	6.9
Gross profit/(loss)	(0.8)	2.7
Operating income/(loss)	(1.4)	2.0
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (13.0)	$ (10.9)