Innospec (IOSP) 10-Q 4 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 28, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Trading Symbol	IOSP
Entity Registrant Name	INNOSPEC INC.
Entity Central Index Key	1,054,905
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		23,970,881

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 212.1	$ 269.2
Cost of goods sold	(135.9)	(187.4)
Gross profit	76.2	81.8
Operating expenses:
Selling, general and administrative	(43.9)	(48.7)
Research and development	(6.9)	(6.2)
Adjustment to fair value of contingent consideration	1.6	(3.5)
Loss on disposal of subsidiary	(1.4)	0
Total operating expenses	(50.6)	(58.4)
Operating income	25.6	23.4
Other net (expense)/income	(0.3)	1.5
Interest expense, net	(0.8)	(1)
Income before income taxes	24.5	23.9
Income taxes	(5.6)	(6)
Net income	$ 18.9	$ 17.9
Earnings per share:
Basic	$ 0.79	$ 0.74
Diluted	$ 0.77	$ 0.72
Weighted average shares outstanding (in thousands):
Basic	24,019	24,301
Diluted	24,483	24,808

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 18.9	$ 17.9
Other comprehensive income/(loss):
Changes in cumulative translation adjustment	1.6	(8)
Amortization of prior service credit, net of tax of $0.1 million and $0.1 million, respectively	(0.2)	(0.2)
Amortization of actuarial net losses, net of tax of $(0.2) million and $(0.3) million, respectively	0.5	1
Total other comprehensive income	1.9	(7.2)
Total comprehensive income	$ 20.8	$ 10.7

Consolidated Statements of Com4

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Amortization of prior service credit, tax	$ 0.1	$ 0.1
Amortization of actuarial net losses, tax	$ (0.2)	$ (0.3)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 113.4	$ 136.9
Short-term investments	1.6	4.8
Trade and other accounts receivable (less allowances of $4.0 million and $3.6 million, respectively)	146.4	137.4
Inventories (less allowances of $8.6 million and $8.8 million, respectively):
Finished goods	104.2	104.4
Work in progress	1.6	2.7
Raw materials	46.8	52.8
Total inventories	152.6	159.9
Current portion of deferred tax assets	8.7	8.8
Prepaid expenses	5.5	6.1
Prepaid income taxes	4.8	3
Other current assets	0	1.8
Total current assets	433	458.7
Property, plant and equipment:
Gross cost	165.7	161
Less accumulated depreciation	(89.1)	(85)
Net property, plant and equipment	76.6	76
Goodwill	267.5	267.4
Other intangible assets	162.6	168.7
Deferred finance costs	1.3	1.4
Deferred tax assets, net of current portion	1.4	1.4
Pension asset	57.9	55.5
Other non-current assets	0.7	0.9
Total assets	1,001	1,030
Current liabilities:
Bank overdraft	6.8	0
Accounts payable	49.9	52.2
Accrued liabilities	65.4	84.1
Current portion of finance leases	0.9	0.7
Current portion of plant closure provisions	5.4	6.4
Current portion of accrued income taxes	9.9	7.9
Current portion of acquisition-related contingent consideration	8.9	54.6
Current portion of deferred income	0.2	0.2
Total current liabilities	147.4	206.1
Long-term debt, net of current portion	146	133
Finance leases, net of current portion	2.3	2.4
Plant closure provisions, net of current portion	32.7	31.3
Unrecognized tax benefits, net of current portion	3.9	3.9
Deferred tax liabilities, net of current portion	38.1	37.7
Pension liability	10	9.2
Deferred income, net of current portion	0.6	0.6
Other non-current liabilities	0.9	0.5
Total liabilities	381.9	424.7
Equity:
Common stock, $0.01 par value, authorized 40,000,000 shares, issued 29,554,500 shares	0.3	0.3
Additional paid-in capital	311.4	311
Treasury stock (5,583,618 and 5,453,078 shares at cost, respectively)	(99.2)	(91.8)
Retained earnings	515.3	496.4
Accumulated other comprehensive loss	(109)	(110.9)
Total Innospec stockholders' equity	618.8	605
Non-controlling interest	0.3	0.3
Total equity	619.1	605.3
Total liabilities and equity	$ 1,001	$ 1,030

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowances for doubtful accounts	$ 4	$ 3.6
Inventory allowances	$ 8.6	$ 8.8
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	29,554,500	29,554,500
Treasury stock, shares	5,583,618	5,453,078

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Cash Flows from Operating Activities
Net income		$ 18.9	$ 17.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	[1]	9.2	8.5
Adjustment to fair value of contingent consideration		(1.6)	3.5
Deferred taxes		0.3	1.1
Excess tax benefit from stock-based payment arrangements		(0.1)	(0.7)
Loss on disposal of subsidiary		1.4	0
Cash contributions to defined benefit pension plans		(0.3)	(2.7)
Non-cash expense of defined benefit pension plans		(1.6)	0.2
Stock option compensation		0.9	0.9
Changes in assets and liabilities, net of effects of acquired and divested companies:
Trade and other accounts receivable		(9.1)	14.1
Inventories		7.9	6.4
Prepaid expenses		0.7	1.5
Accounts payable and accrued liabilities		(21.1)	(33.1)
Accrued income taxes		0.4	0.2
Plant closure provisions		0.3	0.5
Unrecognized tax benefits		0	0.1
Other non-current assets and liabilities		0.4	(0.2)
Net cash provided by operating activities		6.6	18.2
Cash Flows from Investing Activities
Capital expenditures		(3.1)	(3.4)
Business combinations, net of cash acquired		1.8	0
Internally developed software		0	(2.7)
Purchase of short-term investments		0	(1.8)
Sale of short-term investments		3.1	1.1
Net cash provided by/(used in) investing activities		1.8	(6.8)
Cash Flows from Financing Activities
Proceeds from revolving credit facility		18	0
Repayments of revolving credit facility		(5)	0
Receipt of short-term borrowing		6.8	0
Repayments of finance leases and term loans		(0.2)	(0.2)
Payment of acquisition-related contingent consideration		(44)	0
Excess tax benefit from stock-based payment arrangements		0.1	0.7
Issue of treasury stock		0.2	0.7
Repurchase of common stock		(8.2)	(6.3)
Net cash used in financing activities		(32.3)	(5.1)
Effect of foreign currency exchange rate changes on cash		0.4	(1.4)
Net change in cash and cash equivalents		(23.5)	4.9
Cash and cash equivalents at beginning of period		136.9	41.6
Cash and cash equivalents at end of period		$ 113.4	$ 46.5
[1]	Amortization of deferred finance costs of $0.1 million (2015 - $0.2 million) are included in depreciation and amortization in the cash flow statement but in interest expense in the income statement.

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Cash Flows [Abstract]
Amortization of deferred finance costs	$ 0.1	$ 0.2

Consolidated Statement of Equit

Consolidated Statement of Equity - 3 months ended Mar. 31, 2016 - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Non-controlling Interest [Member]
Beginning Balance at Dec. 31, 2015	$ 605.3	$ 0.3	$ 311	$ (91.8)	$ 496.4	$ (110.9)	$ 0.3
Net income	18.9				18.9
Changes in cumulative translation adjustment	1.6					1.6
Treasury stock reissued	0.2		(0.6)	0.8
Treasury stock repurchased	(8.2)			(8.2)
Excess tax benefit from stock-based payment arrangements	0.1		0.1
Stock option compensation	0.9		0.9
Amortization of prior service credit, net of tax	(0.2)					(0.2)
Amortization of actuarial net losses, net of tax	0.5					0.5
Ending Balance at Mar. 31, 2016	$ 619.1	$ 0.3	$ 311.4	$ (99.2)	$ 515.3	$ (109)	$ 0.3

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	NOTE 1 – BASIS OF PRESENTATION The accompanying unaudited interim consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X under the Securities Exchange Act of 1934. Accordingly, they do not include all the information and notes necessary for a comprehensive presentation of financial position, results of operations and cash flows. It is our opinion, however, that all adjustments (consisting of normal, recurring adjustments, unless otherwise disclosed) have been made which are necessary for the financial statements to be fairly stated. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K filed on February 17, 2016. The results for the interim period covered by this report are not necessarily indicative of the results to be expected for the full year. When we use the terms “Innospec,” “the Corporation,” “the Company,” “Registrant,” “we,” “us” and “our,” we are referring to Innospec Inc. and its consolidated subsidiaries unless otherwise indicated or the context otherwise requires.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment Reporting	NOTE 2 – SEGMENT REPORTING Innospec divides its business into three segments for management and reporting purposes: Fuel Specialties, Performance Chemicals and Octane Additives. The Fuel Specialties and Performance Chemicals segments operate in markets where we actively seek growth opportunities although their ultimate customers are different. The Octane Additives segment is expected to decline in the near future as our one remaining refinery customer transitions to unleaded fuel. The Company evaluates the performance of its segments based on operating income. The following table analyzes sales and other financial information by the Company’s reportable segments: Three Months Ended (in millions) 2016 2015 Net sales: Fuel Specialties $ 149.8 $ 199.4 Performance Chemicals 44.5 57.6 Octane Additives 17.8 12.2 $ 212.1 $ 269.2 Gross profit: Fuel Specialties $ 51.2 $ 61.5 Performance Chemicals 13.2 14.5 Octane Additives 11.8 5.8 $ 76.2 $ 81.8 Operating income: Fuel Specialties $ 16.7 $ 23.5 Performance Chemicals 6.1 6.4 Octane Additives 11.0 5.1 Pension credit 1.8 0.0 Corporate costs (10.2 ) (8.1 ) Adjustment to fair value of contingent consideration 1.6 (3.5 ) Loss on disposal of subsidiary (1.4 ) 0.0 Total operating income $ 25.6 $ 23.4 The pension credit relates to the United Kingdom defined benefit pension plan which is closed to future service accrual. The charges related to our other much smaller pension arrangements in the U.S. and overseas are included in the segment and income statement captions consistent with the related employees’ costs. The following table presents a summary of the depreciation and amortization charges incurred by the Company’s reportable segments: Three Months Ended (in millions) 2016 2015 Depreciation: Fuel Specialties $ 2.3 $ 1.9 Performance Chemicals 0.5 0.8 Octane Additives 0.1 0.1 Corporate 0.2 0.4 $ 3.1 $ 3.2 Amortization: Fuel Specialties $ 3.2 $ 3.2 Performance Chemicals 1.0 1.0 Corporate 1.8 0.9 $ 6.0 $ 5.1

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 3 – EARNINGS PER SHARE Basic earnings per share is based on the weighted average number of common shares outstanding during the period. Diluted earnings per share includes the effect of options that are dilutive and outstanding during the period. Per share amounts are computed as follows: Three Months Ended 2016 2015 Numerator (in millions): Net income available to common stockholders $ 18.9 $ 17.9 Denominator (in thousands): Weighted average common shares outstanding 24,019 24,301 Dilutive effect of stock options and awards 464 507 Denominator for diluted earnings per share 24,483 24,808 Net income per share, basic: $ 0.79 $ 0.74 Net income per share, diluted: $ 0.77 $ 0.72 In the three months ended March 31, 2016, the average number of anti-dilutive options excluded from the calculation of diluted earnings per share was 0 (three months ended March 31, 2015 – 33,734).

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	NOTE 4 – GOODWILL The following table summarizes goodwill at the balance sheet dates: (in millions) March 31, December 31, Gross cost (1) $ 504.0 $ 503.9 Accumulated impairment losses (236.5 ) (236.5 ) Net book amount $ 267.5 $ 267.4 (1) Gross cost for 2016 and 2015 is net of $298.5 million of historical accumulated amortization. The movement in gross cost for the period is due to foreign currency translation of $0.1 million.

Other Intangible Assets

Other Intangible Assets	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Other Intangible Assets	NOTE 5 – OTHER INTANGIBLE ASSETS The following table summarizes the other intangible assets movement year on year: Three Months Ended March 31 (in millions) 2016 2015 Gross cost at January 1 $ 248.6 $ 247.6 Capitalization of internally developed software 0.0 2.7 Exchange effect 0.0 (0.1 ) Gross cost at March 31 248.6 250.2 Accumulated amortization at January 1 (79.9 ) (66.5 ) Amortization expense (6.0 ) (5.1 ) Exchange effect (0.1 ) 0.0 Accumulated amortization at March 31 (86.0 ) (71.6 ) Net book amount at March 31 $ 162.6 $ 178.6 Amortization expense Three Months Ended (in millions) 2016 2015 Product rights $ (0.9 ) $ (0.9 ) Brand names (0.3 ) (0.3 ) Technology (0.9 ) (0.9 ) Customer relationships (1.7 ) (1.7 ) Non-compete agreements (0.2 ) (0.2 ) Marketing related (0.2 ) (0.2 ) Internally developed software (1.8 ) (0.9 ) Total $ (6.0 ) $ (5.1 )

Pension Plans

Pension Plans	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Pension Plans	NOTE 6 – PENSION PLANS The Company maintains a defined benefit pension plan (the “Plan”) covering a number of its current and former employees in the United Kingdom, although it does also have other much smaller pension arrangements in the U.S. and overseas. The Plan is closed to future service accrual but has a large number of deferred and current pensioners. Three Months Ended (in millions) 2016 2015 Plan net pension credit/(charge): Service cost $ (0.2 ) $ (0.4 ) Interest cost on projected benefit obligation (5.4 ) (7.0 ) Expected return on plan assets 7.8 8.4 Amortization of prior service credit 0.3 0.3 Amortization of actuarial net losses (0.7 ) (1.3 ) $ 1.8 $ 0.0 The amortization of prior service credit and actuarial net losses is a reclassification out of accumulated other comprehensive loss into selling, general and administrative expenses. The Company also maintains an unfunded defined benefit pension plan covering a number of its current and former employees in Germany (the “German plan”). The German plan is closed to new entrants and has no assets. The net pension charge for the German plan for the three months ended March 31, 2016, was $0.2 million (three months ended March 31, 2015 - $0.2 million).

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 7 – INCOME TAXES A roll-forward of unrecognized tax benefits and associated accrued interest and penalties is as follows: (in millions) Unrecognized Interest and Total Opening balance at January 1, 2016 $ 3.6 $ 0.3 $ 3.9 Additions for current period tax positions 0.0 0.0 0.0 Closing balance at March 31, 2016 3.6 0.3 3.9 Current 0.0 0.0 0.0 Non-current $ 3.6 $ 0.3 $ 3.9 All of the unrecognized tax benefits, interest and penalties, would impact our effective tax rate if recognized. We recognize accrued interest and penalties associated with uncertain tax positions as part of income taxes in our consolidated statements of income. The Company or one of its subsidiaries files income tax returns with the U.S. federal government, and various state and foreign jurisdictions. One of the Company’s U.S. subsidiaries is currently subject to a state tax examination in respect of 2012 through to 2014 inclusive. The Company currently anticipates that adjustments, if any, arising out of this tax audit would not result in a material change to the Company’s financial position as at March 31, 2016. As previously disclosed, one of the Company’s German subsidiaries are subject to a tax audit in respect of 2010 through to 2014 inclusive. The Company currently anticipates that adjustments, if any, arising out of this tax audit would not result in a material change to the Company’s financial position as at March 31, 2016. The Company and its U.S. subsidiaries remain open to examination by the IRS for years 2012 onwards. The Company’s subsidiaries in foreign tax jurisdictions are open to examination including France (2013 onwards), Germany (2010 onwards), Switzerland (2014 onwards) and the United Kingdom (2013 onwards). The Company is in a position to control whether or not to repatriate foreign earnings and we currently do not expect to make a repatriation in the foreseeable future. No taxes have been provided for on the unremitted earnings of our overseas subsidiaries as any tax basis differences relating to investments in these overseas subsidiaries are considered to be permanent in duration. The amount of unremitted earnings at December 31, 2015 was approximately $775 million. If these earnings are remitted, additional taxes could result after offsetting foreign income taxes paid although the calculation of the additional taxes is not practicable to compute at this time.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Long-Term Debt	NOTE 8 – LONG-TERM DEBT Long-term debt consists of the following: (in millions) March 31, December Revolving credit facility $ 146.0 $ 133.0

Plant Closure Provisions

Plant Closure Provisions	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Plant Closure Provisions	NOTE 9 – PLANT CLOSURE PROVISIONS The liability for estimated closure costs of Innospec’s manufacturing facilities includes costs for decontamination and environmental remediation activities (“remediation”). The principal site giving rise to remediation liabilities is the manufacturing site at Ellesmere Port in the United Kingdom. There are also remediation liabilities on a much smaller scale in respect of our other manufacturing sites in the U.S. and Europe. Movements in the provisions are summarized as follows: Three Months Ended (in millions) 2016 2015 Total at January 1 $ 37.7 $ 34.1 Charge for the period 1.1 1.1 Utilized in the period (0.8 ) (0.5 ) Exchange effect 0.1 (0.4 ) Total at March 31 38.1 34.3 Due within one year (5.4 ) (4.9 ) Due after one year $ 32.7 $ 29.4 Amounts due within one year refer to provisions where expenditure is expected to arise within one year of the balance sheet date.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 10 – FAIR VALUE MEASUREMENTS The following table presents the carrying amount and fair values of the Company’s assets and liabilities measured on a recurring basis: March 31, 2016 December 31, 2015 (in millions) Carrying Fair Carrying Fair Assets Non-derivatives: Cash and cash equivalents $ 113.4 $ 113.4 $ 136.9 $ 136.9 Short-term investments 1.6 1.6 4.8 4.8 Liabilities Non-derivatives: Bank overdraft $ 6.8 $ 6.8 $ 0.0 $ 0.0 Long-term debt (including current portion) 146.0 146.0 133.0 133.0 Finance leases (including current portion) 3.2 3.2 3.1 3.1 Derivatives (Level 1 measurement): Other non-current liabilities: Foreign currency forward exchange contracts 0.5 0.5 0.3 0.3 Non-financial liabilities (Level 3 measurement): Acquisition-related contingent consideration (including current portion) 8.9 8.9 54.6 54.6 Stock equivalent units 5.1 5.1 7.8 7.8 The following methods and assumptions were used to estimate the fair values of financial instruments: Cash and cash equivalents, short-term investments and bank overdraft: Long-term debt and finance leases: Derivatives: Acquisition-related contingent consideration: Stock equivalent units:

Derivative Instruments and Risk

Derivative Instruments and Risk Management	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Risk Management	NOTE 11 – DERIVATIVE INSTRUMENTS AND RISK MANAGEMENT The Company enters into various foreign currency forward exchange contracts to minimize currency exchange rate exposure from expected future cash flows. As at March 31, 2016 the contracts have maturity dates of up to twelve months at the date of inception. These foreign currency forward exchange contracts have not been designated as hedging instruments, and their impact on the income statement for the first three months of 2016 was a gain of $1.5 million.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 12 – COMMITMENTS AND CONTINGENCIES Legal matters While we are involved from time to time in claims and legal proceedings that result from, and are incidental to, the conduct of our business including business and commercial litigation, employee and product liability claims, there are no material pending legal proceedings to which the Company or any of its subsidiaries is a party, or of which any of their property is subject. It is possible, however, that an adverse resolution of an unexpectedly large number of such individual claims or proceedings could in the aggregate have a material adverse effect on the results of operations for a particular year or quarter. Guarantees The Company and certain of the Company’s consolidated subsidiaries are contingently liable for certain obligations of affiliated companies primarily in the form of guarantees of debt and performance under contracts entered into as a normal business practice. This includes guarantees of non-U.S. excise taxes and customs duties. As at March 31, 2016, such guarantees which are not recognized as liabilities in the consolidated financial statements amounted to $4.1 million. Under the terms of the guarantee arrangements, generally the Company would be required to perform should the affiliated company fail to fulfil its obligations under the arrangements. In some cases, the guarantee arrangements have recourse provisions that would enable the Company to recover any payments made under the terms of the guarantees from securities held of the guaranteed parties’ assets. The Company and its affiliates have numerous long-term sales and purchase commitments in their various business activities, which are expected to be fulfilled with no adverse consequences material to the Company.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	NOTE 13 – STOCK-BASED COMPENSATION PLANS The Company grants stock options and stock equivalent units (“SEUs”) from time to time as a long-term performance incentive. In certain cases the grants are subject to performance conditions such as the Company’s stock price. Where performance conditions apply the Monte Carlo simulation model is used to determine the fair values. Otherwise the Black-Scholes model is used to determine the fair values. Stock option plans The following table summarizes the transactions of the Company’s stock option plans for the three months ended March 31, 2016: Number of Weighted Weighted Grant-Date Outstanding at December 31, 2015 667,439 $ 19.87 $ 20.19 Granted - at discount 54,642 $ 0.00 $ 35.91 - at market value 23,852 $ 44.18 $ 9.11 Exercised (47,212 ) $ 5.26 $ 28.63 Forfeited (10,832 ) $ 13.82 $ 1.00 Outstanding at March 31, 2016 687,889 $ 20.23 $ 20.37 At March 31, 2016, there were 111,664 stock options that were exercisable, of which 26,362 had performance conditions attached. The stock option compensation cost for the first three months of 2016 was $0.9 million (2015 – $0.9 million). The total intrinsic value of options exercised in the first three months of 2016 was $1.5 million (2015 – $2.0 million). The total compensation cost related to non-vested stock options not yet recognized at March 31, 2016 was $5.5 million and this cost is expected to be recognized over the weighted-average period of 2.30 years. Stock equivalent units The following table summarizes the transactions of the Company’s SEUs for the three months ended March 31, 2016: Number Weighted Weighted Grant-Date Outstanding at December 31, 2015 279,750 $ 3.79 $ 31.72 Granted - at discount 63,653 $ 0.00 $ 35.71 - at market value 7,316 $ 44.18 $ 9.11 Exercised (38,638 ) $ 2.24 $ 26.44 Forfeited (3,310 ) $ 11.97 $ 28.48 Outstanding at March 31, 2016 308,771 $ 4.07 $ 32.70 At March 31, 2016 there were 74,920 SEUs that are exercisable, of which 66,318 had performance conditions attached. The charges for SEUs are spread over the life of the award subject to a revaluation to fair value each quarter. The revaluation may result in a charge or a credit to the income statement in the quarter dependent upon our share price and other performance criteria. The SEU compensation cost for the first three months of 2016 was a credit of $1.0 million (2015 - $1.0 million). The total intrinsic value of SEUs exercised in the first three months of 2016 was $1.1 million (2015 - $1.9 million). The weighted-average remaining vesting period of non-vested SEUs is 2.08 years. Additional exceptional long-term incentive plan A maximum of $3.0 million of our cash-settled long-term incentives is accounted for as share-based compensation and the fair value is calculated on a quarterly basis using a Monte Carlo model. The fair values at each of the balance sheet dates are summarized as follows: (in millions) 2016 2015 Balance at January 1 $ 1.0 $ 0.1 Compensation (credit)/charge for the period (0.7 ) 0.1 Balance at March 31 $ 0.3 $ 0.2 The following assumptions were used in the Monte Carlo model at March 31: 2016 2015 Dividend yield 1.41 % 1.19 % Volatility of Innospec’s share price 25.37 % 25.91 % Risk free interest rate 0.87 % 0.89 %

Reclassifications out of Accumu

Reclassifications out of Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Reclassifications out of Accumulated Other Comprehensive Loss	NOTE 14 – RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS Reclassifications out of accumulated other comprehensive loss for the first three months of 2016 were: (in millions) Amount Affected Line Item in the Details about AOCL Components from AOCL Net Income is Presented Defined benefit pension plan items: Amortization of prior service credit $ (0.3 ) See (1) Amortization of actuarial net losses 0.7 See (1) 0.4 Total before tax (0.1 ) Income tax expense 0.3 Net of tax Total reclassifications $ 0.3 Net of tax (1) These items are included in the computation of net periodic pension cost. See Note 7 of the Notes to the Consolidated Financial Statements for additional information. Changes in accumulated other comprehensive loss for the first three months of 2016, net of tax, were: (in millions) Defined Cumulative Total Balance at December 31, 2015 $ (50.9 ) $ (60.0 ) $ (110.9 ) Other comprehensive income before reclassifications 0.0 1.6 1.6 Amounts reclassified from AOCL 0.3 0.0 0.3 Total other comprehensive income 0.3 1.6 1.9 Balance at March 31, 2016 $ (50.6 ) $ (58.4 ) $ (109.0 )

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	3 Months Ended
	Mar. 31, 2016
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Pronouncements	NOTE 15 – RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS On February 25, 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Revision to Lease Accounting, which amends ASC Topic 842, Leases. The ASU requires lessees to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. Transition will require application of the new guidance at the beginning of the earliest comparative period presented. The Company has not yet determined the effect of the standard on its ongoing financial reporting. On March 30, 2016, the FASB issued Accounting Standards Update (ASU) 2016-09, Improvements to Employee Share-based Payment Accounting, which amends ASC Topic 718, Compensation – Stock Compensation. The ASU includes provisions intended to simplify various aspects related to how Share-based payments are accounted for and presented in the financial statements. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 2016, and interim periods within that reporting period. Early adoption will be permitted in any interim or annual period, with any adjustments reflected as of the beginning of the fiscal year of adoption. The Company has not yet determined the effect of the standard on its ongoing financial reporting.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 16 – RELATED PARTY TRANSACTIONS Mr. Robert I. Paller has been a non-executive director of the Company since November 1, 2009. The Company has retained and continues to retain Smith, Gambrell & Russell, LLP (“SGR”), a law firm with which Mr. Paller holds a position. In the first three months of 2016 the Company incurred fees from SGR of $0.2 million (2015 – $0.2 million). As at March 31, 2016, the amount due to SGR from the Company was $0.3 million (December 31, 2015 - $0.1 million).

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	NOTE 17 – SUBSEQUENT EVENTS With effect from the beginning of the second quarter of 2016 the Company is changing its reporting segments to reflect the development of its management and strategy. The new reporting structure will be: • Fuel Specialities, including the Polymers business previously reported in Performance Chemicals • Performance Chemicals • Oilfield Services, which was previously reported within Fuel Specialties • Octane Additives (no change) Our historical segment reporting will be retrospectively revised during the remainder of 2016 to reflect the new organizational structure.

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment Reporting	The following table analyzes sales and other financial information by the Company’s reportable segments: Three Months Ended (in millions) 2016 2015 Net sales: Fuel Specialties $ 149.8 $ 199.4 Performance Chemicals 44.5 57.6 Octane Additives 17.8 12.2 $ 212.1 $ 269.2 Gross profit: Fuel Specialties $ 51.2 $ 61.5 Performance Chemicals 13.2 14.5 Octane Additives 11.8 5.8 $ 76.2 $ 81.8 Operating income: Fuel Specialties $ 16.7 $ 23.5 Performance Chemicals 6.1 6.4 Octane Additives 11.0 5.1 Pension credit 1.8 0.0 Corporate costs (10.2 ) (8.1 ) Adjustment to fair value of contingent consideration 1.6 (3.5 ) Loss on disposal of subsidiary (1.4 ) 0.0 Total operating income $ 25.6 $ 23.4
Summary of Segment Depreciation and Amortization	The following table presents a summary of the depreciation and amortization charges incurred by the Company’s reportable segments: Three Months Ended (in millions) 2016 2015 Depreciation: Fuel Specialties $ 2.3 $ 1.9 Performance Chemicals 0.5 0.8 Octane Additives 0.1 0.1 Corporate 0.2 0.4 $ 3.1 $ 3.2 Amortization: Fuel Specialties $ 3.2 $ 3.2 Performance Chemicals 1.0 1.0 Corporate 1.8 0.9 $ 6.0 $ 5.1

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Summary of Earnings Per Share	Per share amounts are computed as follows: Three Months Ended 2016 2015 Numerator (in millions): Net income available to common stockholders $ 18.9 $ 17.9 Denominator (in thousands): Weighted average common shares outstanding 24,019 24,301 Dilutive effect of stock options and awards 464 507 Denominator for diluted earnings per share 24,483 24,808 Net income per share, basic: $ 0.79 $ 0.74 Net income per share, diluted: $ 0.77 $ 0.72

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill	The following table summarizes goodwill at the balance sheet dates: (in millions) March 31, December 31, Gross cost (1) $ 504.0 $ 503.9 Accumulated impairment losses (236.5 ) (236.5 ) Net book amount $ 267.5 $ 267.4 (1) Gross cost for 2016 and 2015 is net of $298.5 million of historical accumulated amortization.

Other Intangible Assets (Tables

Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Other Intangible Assets	The following table summarizes the other intangible assets movement year on year: Three Months Ended March 31 (in millions) 2016 2015 Gross cost at January 1 $ 248.6 $ 247.6 Capitalization of internally developed software 0.0 2.7 Exchange effect 0.0 (0.1 ) Gross cost at March 31 248.6 250.2 Accumulated amortization at January 1 (79.9 ) (66.5 ) Amortization expense (6.0 ) (5.1 ) Exchange effect (0.1 ) 0.0 Accumulated amortization at March 31 (86.0 ) (71.6 ) Net book amount at March 31 $ 162.6 $ 178.6
Schedule of Amortization Expense	Amortization expense Three Months Ended (in millions) 2016 2015 Product rights $ (0.9 ) $ (0.9 ) Brand names (0.3 ) (0.3 ) Technology (0.9 ) (0.9 ) Customer relationships (1.7 ) (1.7 ) Non-compete agreements (0.2 ) (0.2 ) Marketing related (0.2 ) (0.2 ) Internally developed software (1.8 ) (0.9 ) Total $ (6.0 ) $ (5.1 )

Pension Plans (Tables)

Pension Plans (Tables)	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Pension Plan	The Plan is closed to future service accrual but has a large number of deferred and current pensioners. Three Months Ended (in millions) 2016 2015 Plan net pension credit/(charge): Service cost $ (0.2 ) $ (0.4 ) Interest cost on projected benefit obligation (5.4 ) (7.0 ) Expected return on plan assets 7.8 8.4 Amortization of prior service credit 0.3 0.3 Amortization of actuarial net losses (0.7 ) (1.3 ) $ 1.8 $ 0.0

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Roll-Forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties	A roll-forward of unrecognized tax benefits and associated accrued interest and penalties is as follows: (in millions) Unrecognized Interest and Total Opening balance at January 1, 2016 $ 3.6 $ 0.3 $ 3.9 Additions for current period tax positions 0.0 0.0 0.0 Closing balance at March 31, 2016 3.6 0.3 3.9 Current 0.0 0.0 0.0 Non-current $ 3.6 $ 0.3 $ 3.9

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Long-term debt consists of the following: (in millions) March 31, December Revolving credit facility $ 146.0 $ 133.0

Plant Closure Provisions (Table

Plant Closure Provisions (Tables)	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Movements in Plant Closure and Restructuring Provisions	Movements in the provisions are summarized as follows: Three Months Ended (in millions) 2016 2015 Total at January 1 $ 37.7 $ 34.1 Charge for the period 1.1 1.1 Utilized in the period (0.8 ) (0.5 ) Exchange effect 0.1 (0.4 ) Total at March 31 38.1 34.3 Due within one year (5.4 ) (4.9 ) Due after one year $ 32.7 $ 29.4

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis	The following table presents the carrying amount and fair values of the Company’s assets and liabilities measured on a recurring basis: March 31, 2016 December 31, 2015 (in millions) Carrying Fair Carrying Fair Assets Non-derivatives: Cash and cash equivalents $ 113.4 $ 113.4 $ 136.9 $ 136.9 Short-term investments 1.6 1.6 4.8 4.8 Liabilities Non-derivatives: Bank overdraft $ 6.8 $ 6.8 $ 0.0 $ 0.0 Long-term debt (including current portion) 146.0 146.0 133.0 133.0 Finance leases (including current portion) 3.2 3.2 3.1 3.1 Derivatives (Level 1 measurement): Other non-current liabilities: Foreign currency forward exchange contracts 0.5 0.5 0.3 0.3 Non-financial liabilities (Level 3 measurement): Acquisition-related contingent consideration (including current portion) 8.9 8.9 54.6 54.6 Stock equivalent units 5.1 5.1 7.8 7.8

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2016
Stock Options Plan [Member]
Summary of Transactions of Company's Stock Option Plans	The following table summarizes the transactions of the Company’s stock option plans for the three months ended March 31, 2016: Number of Weighted Weighted Grant-Date Outstanding at December 31, 2015 667,439 $ 19.87 $ 20.19 Granted - at discount 54,642 $ 0.00 $ 35.91 - at market value 23,852 $ 44.18 $ 9.11 Exercised (47,212 ) $ 5.26 $ 28.63 Forfeited (10,832 ) $ 13.82 $ 1.00 Outstanding at March 31, 2016 687,889 $ 20.23 $ 20.37
Stock Equivalent Units [Member]
Summarizes Transactions of SEUs	The following table summarizes the transactions of the Company’s SEUs for the three months ended March 31, 2016: Number Weighted Weighted Grant-Date Outstanding at December 31, 2015 279,750 $ 3.79 $ 31.72 Granted - at discount 63,653 $ 0.00 $ 35.71 - at market value 7,316 $ 44.18 $ 9.11 Exercised (38,638 ) $ 2.24 $ 26.44 Forfeited (3,310 ) $ 11.97 $ 28.48 Outstanding at March 31, 2016 308,771 $ 4.07 $ 32.70
Additional Exceptional Long-Term Incentive Plan [Member]
Summary of Fair Value of Balance Sheet Dates	The fair values at each of the balance sheet dates are summarized as follows: (in millions) 2016 2015 Balance at January 1 $ 1.0 $ 0.1 Compensation (credit)/charge for the period (0.7 ) 0.1 Balance at March 31 $ 0.3 $ 0.2
Assumptions Used in the Monte Carlo Model	The following assumptions were used in the Monte Carlo model at March 31: 2016 2015 Dividend yield 1.41 % 1.19 % Volatility of Innospec’s share price 25.37 % 25.91 % Risk free interest rate 0.87 % 0.89 %

Reclassifications out of Accu37

Reclassifications out of Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Summary of Reclassifications Out of Accumulated Other Comprehensive Loss	Reclassifications out of accumulated other comprehensive loss for the first three months of 2016 were: (in millions) Amount Affected Line Item in the Details about AOCL Components from AOCL Net Income is Presented Defined benefit pension plan items: Amortization of prior service credit $ (0.3 ) See (1) Amortization of actuarial net losses 0.7 See (1) 0.4 Total before tax (0.1 ) Income tax expense 0.3 Net of tax Total reclassifications $ 0.3 Net of tax (1) These items are included in the computation of net periodic pension cost. See Note 7 of the Notes to the Consolidated Financial Statements for additional information.
Changes in Accumulated Other Comprehensive Loss	Changes in accumulated other comprehensive loss for the first three months of 2016, net of tax, were: (in millions) Defined Cumulative Total Balance at December 31, 2015 $ (50.9 ) $ (60.0 ) $ (110.9 ) Other comprehensive income before reclassifications 0.0 1.6 1.6 Amounts reclassified from AOCL 0.3 0.0 0.3 Total other comprehensive income 0.3 1.6 1.9 Balance at March 31, 2016 $ (50.6 ) $ (58.4 ) $ (109.0 )

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Segment
Segment Reporting [Abstract]
Number of segments	3

Segment Reporting - Segment Rep

Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 212.1	$ 269.2
Gross profit	76.2	81.8
Adjustment to fair value of contingent consideration	1.6	(3.5)
Loss on disposal of subsidiary	(1.4)	0
Operating income	25.6	23.4
Operating Segments [Member] | Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	149.8	199.4
Gross profit	51.2	61.5
Operating income	16.7	23.5
Operating Segments [Member] | Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	44.5	57.6
Gross profit	13.2	14.5
Operating income	6.1	6.4
Operating Segments [Member] | Octane Additives [Member]
Segment Reporting Information [Line Items]
Net sales	17.8	12.2
Gross profit	11.8	5.8
Operating income	11	5.1
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Pension credit	1.8	0
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	$ (10.2)	$ (8.1)

Segment Reporting - Summary of

Segment Reporting - Summary of Segment Depreciation and Amortization (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Summary of segment depreciation and amortization
Depreciation	$ 3.1	$ 3.2
Amortization	6	5.1
Operating Segments [Member] | Fuel Specialties [Member]
Summary of segment depreciation and amortization
Depreciation	2.3	1.9
Amortization	3.2	3.2
Operating Segments [Member] | Performance Chemicals [Member]
Summary of segment depreciation and amortization
Depreciation	0.5	0.8
Amortization	1	1
Operating Segments [Member] | Octane Additives [Member]
Summary of segment depreciation and amortization
Depreciation	0.1	0.1
Corporate, Non-Segment [Member]
Summary of segment depreciation and amortization
Depreciation	0.2	0.4
Amortization	$ 1.8	$ 0.9

Earnings Per Share - Summary of

Earnings Per Share - Summary of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator (in millions):
Net income available to common stockholders	$ 18.9	$ 17.9
Denominator (in thousands):
Weighted average common shares outstanding	24,019	24,301
Dilutive effect of stock options and awards	464	507
Denominator for diluted earnings per share	24,483	24,808
Net income per share, basic:	$ 0.79	$ 0.74
Net income per share, diluted:	$ 0.77	$ 0.72

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Average number of anti-dilutive options excluded from the calculation of diluted earnings per share	0	33,734

Goodwill - Summary of Goodwill

Goodwill - Summary of Goodwill (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Gross cost	$ 504	$ 503.9
Accumulated impairment losses	(236.5)	(236.5)
Net book amount	$ 267.5	$ 267.4

Goodwill - Summary of Goodwil44

Goodwill - Summary of Goodwill (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Historical accumulated amortization	$ 298.5	$ 298.5

Goodwill - Additional Informati

Goodwill - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Foreign currency translation adjustment on goodwill	$ 0.1

Other Intangible Assets - Summa

Other Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Gross cost at January 1	$ 248.6	$ 247.6
Capitalization of internally developed software	0	2.7
Exchange effect	0	(0.1)
Gross cost at March 31	248.6	250.2
Accumulated amortization at January 1	(79.9)	(66.5)
Amortization expense	(6)	(5.1)
Exchange effect	(0.1)	0
Accumulated amortization at March 31	(86)	(71.6)
Net book amount at March 31	$ 162.6	$ 178.6	$ 168.7

Other Intangible Assets - Sched

Other Intangible Assets - Schedule of Amortization Expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ (6)	$ (5.1)
Product Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(0.9)	(0.9)
Brand Names [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(0.3)	(0.3)
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(0.9)	(0.9)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(1.7)	(1.7)
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(0.2)	(0.2)
Marketing Related [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	(0.2)	(0.2)
Internally Developed Software [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ (1.8)	$ (0.9)

Pension Plans - Defined Benefit

Pension Plans - Defined Benefit Pension Plan (Detail) - United Kingdom Plan [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Plan net pension credit/(charge):
Service cost	$ (0.2)	$ (0.4)
Interest cost on projected benefit obligation	(5.4)	(7)
Expected return on plan assets	7.8	8.4
Amortization of prior service credit	0.3	0.3
Amortization of actuarial net losses	(0.7)	(1.3)
Net pension credit total	$ 1.8	$ 0

Pension Plans - Additional Info

Pension Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
German Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension charge	$ 0.2	$ 0.2

Income Taxes - Roll-Forward of

Income Taxes - Roll-Forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Opening balance at January 1, 2016	$ 3.9
Additions for current period tax positions	0
Closing balance at March 31, 2016	3.9
Current		$ 0
Non-current		3.9	$ 3.9
Unrecognized tax benefits	3.9	3.9	3.9
Unrecognized Tax Benefits [Member]
Income Tax Contingency [Line Items]
Opening balance at January 1, 2016	3.6
Additions for current period tax positions	0
Closing balance at March 31, 2016	3.6
Current		0
Non-current		3.6
Unrecognized tax benefits	3.6	3.6	3.6
Interest and Penalties [Member]
Income Tax Contingency [Line Items]
Opening balance at January 1, 2016	0.3
Additions for current period tax positions	0
Closing balance at March 31, 2016	0.3
Current		0
Non-current		0.3
Unrecognized tax benefits	$ 0.3	$ 0.3	$ 0.3

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Income tax examination, description	The Company and its U.S. subsidiaries remain open to examination by the IRS for years 2012 onwards. The Company's subsidiaries in foreign tax jurisdictions are open to examination including France (2013 onwards), Germany (2010 onwards), Switzerland (2014 onwards) and the United Kingdom (2013 onwards).
Unremitted earnings		$ 775
France [Member]
Income Tax Contingency [Line Items]
Open tax year	2,013
Germany [Member]
Income Tax Contingency [Line Items]
Open tax year	2,010
Switzerland [Member]
Income Tax Contingency [Line Items]
Open tax year	2,014
United Kingdom [Member]
Income Tax Contingency [Line Items]
Open tax year	2,013

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt	$ 146	$ 133

Plant Closure Provisions - Move

Plant Closure Provisions - Movements in Plant Closure and Restructuring Provisions (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Beginning Balance	$ 37.7	$ 34.1
Charge for the period	1.1	1.1
Utilized in the period	(0.8)	(0.5)
Exchange effect	0.1	(0.4)
Ending Balance	38.1	34.3
Due within one year	(5.4)	(4.9)	$ (6.4)
Due after one year	$ 32.7	$ 29.4	$ 31.3

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Non-derivatives:
Bank overdraft	$ 6.8	$ 0
Recurring [Member] | Carrying Amount [Member]
Non-derivatives:
Cash and cash equivalents	113.4	136.9
Short-term investments	1.6	4.8
Non-derivatives:
Bank overdraft	6.8	0
Long-term debt (including current portion)	146	133
Finance leases (including current portion)	3.2	3.1
Recurring [Member] | Carrying Amount [Member] | Derivatives (Level 1 Measurement) [Member] | Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Foreign currency forward exchange contracts	0.5	0.3
Recurring [Member] | Carrying Amount [Member] | Non-financial Assets and Liabilities (Level 3 Measurement) [Member]
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration (including current portion)	8.9	54.6
Stock equivalent units	5.1	7.8
Recurring [Member] | Fair Value [Member]
Non-derivatives:
Cash and cash equivalents	113.4	136.9
Short-term investments	1.6	4.8
Non-derivatives:
Bank overdraft	6.8	0
Long-term debt (including current portion)	146	133
Finance leases (including current portion)	3.2	3.1
Recurring [Member] | Fair Value [Member] | Derivatives (Level 1 Measurement) [Member] | Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Foreign currency forward exchange contracts	0.5	0.3
Recurring [Member] | Fair Value [Member] | Non-financial Assets and Liabilities (Level 3 Measurement) [Member]
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration (including current portion)	8.9	54.6
Stock equivalent units	$ 5.1	$ 7.8

Derivative Instruments and Ri55

Derivative Instruments and Risk Management - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Derivative [Line Items]
Maturity period of foreign currency forward exchange contracts	12 months
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Exchange Contracts [Member] | Other net (expense)/income [Member]
Derivative [Line Items]
Amount of gain/(loss) recognized in income	$ 1.5

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Mar. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Guarantees	$ 4.1

Stock-Based Compensation Plan57

Stock-Based Compensation Plans - Summary of Transactions of the Company's Stock Option Plans (Detail) - Stock Options Plan [Member]	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Number of Options, Beginning balance | shares	667,439
Exercised, Number of Options | shares	(47,212)
Forfeited, Number of Options | shares	(10,832)
Outstanding, Number of Options, Ending balance | shares	687,889
Outstanding, Weighted Average Exercise Price, Beginning balance	$ 19.87
Exercised, Weighted Average Exercise Price	5.26
Forfeited, Weighted Average Exercise Price	13.82
Outstanding, Weighted Average Exercise Price, Ending balance	20.23
Outstanding, Weighted Average Grant-Date Fair Value	20.19
Exercised	28.63
Forfeited, Weighted Average Grant-Date Fair Value	1
Outstanding, Weighted Average Grant-Date Fair Value	$ 20.37
Discount [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Number of Options | shares	54,642
Granted, Weighted Average Exercise Price	$ 0
Granted, Weighted Average Grant-Date Fair Value	$ 35.91
Market Value [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Number of Options | shares	23,852
Granted, Weighted Average Exercise Price	$ 44.18
Granted, Weighted Average Grant-Date Fair Value	$ 9.11

Stock-Based Compensation Plan58

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option compensation	$ 900,000	$ 900,000
Maximum cash bonus under long-term incentive plan	$ 3,000,000
Stock Options Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number exercisable and fully vested	111,664
Fully vested stock options with performance conditions attached	26,362
Stock option compensation	$ 900,000	900,000
Total intrinsic value exercised	1,500,000	2,000,000
Total compensation cost related to non-vested stock options not yet recognized	$ 5,500,000
Expected compensation cost recognized over the weighted-average period	2 years 3 months 18 days
Stock Equivalent Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fully vested stock options with performance conditions attached	66,318
Total intrinsic value exercised	$ 1,100,000	1,900,000
Expected compensation cost recognized over the weighted-average period	2 years 29 days
Number of exercisable SEUs	74,920
Compensation cost	$ 1,000,000	$ 1,000,000

Stock-Based Compensation Plan59

Stock-Based Compensation Plans - Summarizes Transactions of SEUs (Detail) - Stock Equivalent Units [Member]	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Number of SEUs, Beginning balance | shares	279,750
Granted at discount, Number of SEUs | shares	63,653
Granted at market value, Number of SEUs | shares	7,316
Exercised, Number of SEUs | shares	(38,638)
Forfeited, Number of Options | shares	(3,310)
Outstanding, Number of SEUs, Ending balance | shares	308,771
Outstanding, Weighted Average Exercise Price, Beginning balance	$ 3.79
Granted at discount, Weighted Average Exercise Price	0
Granted at market value, Weighted Average Exercise Price	44.18
Exercised, Weighted Average Exercise Price	2.24
Forfeited, Weighted Average Exercise Price	11.97
Outstanding, Weighted Average Exercise Price, Ending balance	4.07
Outstanding, Weighted Average Grant-Date Fair Value	31.72
Granted at discount, Weighted Average Grant-Date Fair Value	35.71
Granted at market value, Weighted Average Grant-Date Fair Value	9.11
Exercised, Weighted Average Grant-Date Fair Value	26.44
Forfeited, Weighted Average Grant-Date Fair Value	28.48
Outstanding, Weighted Average Grant-Date Fair Value	$ 32.70

Stock-Based Compensation Plan60

Stock-Based Compensation Plans - Fair Value of Liability Cash-Settled Long-Term Incentives (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Balance at January 1	$ 1	$ 0.1
Compensation (credit)/charge for the period	(0.7)	0.1
Balance at March 31	$ 0.3	$ 0.2

Stock-Based Compensation Plan61

Stock-Based Compensation Plans - Assumptions Used in the Monte Carlo Model (Detail) - Monte Carlo Model [Member]	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	1.41%	1.19%
Volatility of Innospec's share price	25.37%	25.91%
Risk free interest rate	0.87%	0.89%

Reclassifications out of Accu62

Reclassifications out of Accumulated Other Comprehensive Loss - Summary of Reclassifications out of Accumulated Other Comprehensive Loss (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	$ (0.3)
Defined Benefit Pension Plan Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	(0.3)
Reclassification Out of Accumulated Other Comprehensive Income/(Loss) [Member] | Defined Benefit Pension Plan Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service credit	(0.3)
Amortization of actuarial net losses	0.7
Total before tax	0.4
Income tax expense	(0.1)
Total reclassifications	$ 0.3

Reclassifications out of Accu63

Reclassifications out of Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Opening balance	$ (110.9)
Other comprehensive income before reclassifications	1.6
Amounts reclassified from AOCL	0.3
Total other comprehensive income	1.9	$ (7.2)
Closing balance	(109)
Defined Benefit Pension Plan Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Opening balance	(50.9)
Other comprehensive income before reclassifications	0
Amounts reclassified from AOCL	0.3
Total other comprehensive income	0.3
Closing balance	(50.6)
Foreign Currency Translation Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Opening balance	(60)
Other comprehensive income before reclassifications	1.6
Amounts reclassified from AOCL	0
Total other comprehensive income	1.6
Closing balance	$ (58.4)

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - Smith, Gambrell & Russell, LLP [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Related Party Transaction [Line Items]
Fees payable to Smith, Gambrell & Russell	$ 0.2	$ 0.2
Amount due to Smith, Gambrell & Russell	$ 0.3		$ 0.1