Segmental Reporting - Segment Reporting (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Net sales	$ 221.3	$ 185.0	$ 442.0	$ 384.4
Gross profit	68.6	59.4	134.3	123.2
Operating income	25.3	22.3	43.3	44.5
Pension charge	(0.9)	(0.7)	(1.7)	(1.4)
Impairment of Octane Additives segment goodwill	0	(0.3)	0	(0.6)
Operating Segments [Member] | Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	145.1	126.2	309.3	266.2
Gross profit	43.9	40.5	95.9	87.5
Operating income	17.5	19.2	43.3	44.1
Operating Segments [Member] | Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	59.4	44.5	115.5	92.3
Gross profit	15.3	11.3	28.9	21.8
Operating income	7.8	6.5	14.3	11.5
Operating Segments [Member] | Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	16.8	14.3	17.2	25.9
Gross profit	9.4	7.6	9.5	13.9
Operating income	8.3	6.1	7.1	10.9
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Pension charge	(0.9)	(0.7)	(1.7)	(1.4)
Impairment of Octane Additives segment goodwill	0	(0.3)	0	(0.6)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (7.4)	$ (8.5)	$ (19.7)	$ (20.0)