Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net sales	$ 254.2	$ 228.2	$ 766.3	$ 670.2
Gross profit	90.4	73.6	259.7	207.9
Operating income	41.2	25.2	122.0	68.5
Pension credit/(charge)	0.0	(0.8)	0.1	(2.5)
Adjustment to fair value of contingent consideration	8.5	0.0	31.6	0.0
Profit on disposal of subsidiary	1.6	0.0	1.6	0.0
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	190.3	156.1	572.0	465.4
Gross profit	69.0	53.2	199.4	149.1
Operating income	27.0	24.5	78.3	67.8
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	43.6	57.0	155.3	172.5
Gross profit	12.4	13.7	41.7	42.6
Operating income	5.4	6.6	19.3	20.9
Operating Segments [Member] \| Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	20.3	15.1	39.0	32.3
Gross profit	9.0	6.7	18.6	16.2
Operating income	8.0	4.9	15.9	12.0
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Pension credit/(charge)	0.0	(0.8)	0.1	(2.5)
Adjustment to fair value of contingent consideration	8.5	0.0	31.6	0.0
Profit on disposal of subsidiary	1.6	0.0	1.6	0.0
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (9.3)	$ (10.0)	$ (24.8)	$ (29.7)

Corporate costs.

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- Definition

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

+ References

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-Publisher FASB

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The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

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Amount of gain (loss) on sale or disposal of equity in securities of subsidiaries.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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The net result for the period of deducting operating expenses from operating revenues.

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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