Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 371.9	$ 363.1	$ 1,122.6	$ 1,081.9
Gross profit/(loss)	119.1	111.0	348.0	318.3
Restructuring charge	0.0	4.8	0.0	4.8
Operating income/(loss)	38.2	33.4	106.1	90.6
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	144.1	134.9	433.4	412.5
Gross profit/(loss)	54.1	48.8	154.5	141.8
Operating income/(loss)	31.1	28.8	88.1	80.7
Operating Segments [Member] \| Fuel Specialties [Member] \| Refinery and Performance [Member]
Segment Reporting Information [Line Items]
Net sales	96.5	97.8	309.0	306.9
Operating Segments [Member] \| Fuel Specialties [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	47.6	37.1	124.4	105.6
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	99.9	114.8	322.7	357.7
Gross profit/(loss)	22.6	25.3	73.2	74.5
Operating income/(loss)	9.3	12.4	33.8	34.2
Operating Segments [Member] \| Performance Chemicals [Member] \| Personal Care [Member]
Segment Reporting Information [Line Items]
Net sales	55.0	60.6	170.9	183.6
Operating Segments [Member] \| Performance Chemicals [Member] \| Home Care [Member]
Segment Reporting Information [Line Items]
Net sales	21.1	28.2	71.2	84.5
Operating Segments [Member] \| Performance Chemicals [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Net sales	23.8	26.0	80.6	89.6
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	121.4	104.2	358.1	292.1
Gross profit/(loss)	41.2	33.5	120.4	93.5
Operating income/(loss)	10.0	7.0	27.9	14.1
Operating Segments [Member] \| Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	6.5	9.2	8.4	19.6
Gross profit/(loss)	1.2	3.4	(0.1)	8.5
Operating income/(loss)	0.8	2.7	(1.9)	6.5
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	(13.0)	(12.7)	(41.8)	(40.1)
Restructuring charge	$ 0.0	$ (4.8)	$ 0.0	$ (4.8)

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