Innospec (IOSP) 10-Q 5 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 30, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'IOSP	'
Entity Registrant Name	'INNOSPEC INC.	'
Entity Central Index Key	'0001054905	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	24,428,284

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Net sales	$228.20	$192.80	$670.20	$577.20
Cost of goods sold	-154.6	-135.4	-462.3	-396.6
Gross profit	73.6	57.4	207.9	180.6
Operating expenses:	'	'	'	'
Selling, general and administrative	-42.4	-31.8	-122.1	-99
Research and development	-6	-5.7	-17.3	-16.6
Impairment of Octane Additives segment goodwill	0	-0.4	0	-1
Total operating expenses	-48.4	-37.9	-139.4	-116.6
Operating income	25.2	19.5	68.5	64
Other net income/(expense)	1	-0.8	2.2	-0.8
Interest expense	-0.9	-0.5	-2.8	-1.4
Interest income	0.1	0.1	0.3	0.3
Income before income taxes	25.4	18.3	68.2	62.1
Income taxes	-4.6	-4.3	-12	-13
Net income	$20.80	$14	$56.20	$49.10
Earnings per share:	'	'	'	'
Basic	$0.85	$0.59	$2.30	$2.09
Diluted	$0.83	$0.58	$2.26	$2.04
Weighted average shares outstanding (in thousands):	'	'	'	'
Basic	24,420	23,621	24,394	23,518
Diluted	24,915	24,096	24,849	24,085

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$20.80	$14	$56.20	$49.10
Other comprehensive income/(loss):	'	'	'	'
Changes in cumulative translation adjustment	-6	2.2	-6.2	-1.6
Changes in unrealized gains/(losses) on derivative instruments, net of tax of $0.0, $0.0, $0.0 and $0.0, respectively	0	0	0	-0.1
Amortization of prior service credit, net of tax of $0.1, $0.1, $0.2 and $0.2, respectively	-0.2	-0.2	-0.8	-0.7
Amortization of actuarial net losses, net of tax of $(0.2), $(0.3), $(0.8) and $(1.0), respectively	1.1	1.4	3.3	4
Total other comprehensive income/(loss)	-5.1	3.4	-3.7	1.6
Total comprehensive income	$15.70	$17.40	$52.50	$50.70

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Changes in unrealized gains/(losses) on derivative instruments, tax	$0	$0	$0	$0
Amortization of prior service credit, tax	0.1	0.1	0.2	0.2
Amortization of actuarial net losses, tax	($0.20)	($0.30)	($0.80)	($1)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$90.40	$80.20
Short-term investments	4.9	6.6
Trade and other accounts receivable (less allowances of $4.4 and $2.0, respectively)	117.3	135.8
Inventories (less allowances of $9.7 and $9.5, respectively):	'	'
Finished goods	118.9	95.3
Work in progress	1.9	1.9
Raw materials	51.1	61.7
Total inventories	171.9	158.9
Current portion of deferred tax assets	8.7	8.7
Prepaid expenses	3.8	5.8
Prepaid income taxes	0.6	11.4
Total current assets	397.6	407.4
Property, plant and equipment:	'	'
Gross cost	159.8	175.1
Less accumulated depreciation	-99.1	-114.7
Net property, plant and equipment	60.7	60.4
Goodwill	187.9	187.9
Other intangible assets	120.2	126.8
Deferred finance costs	1.3	1.8
Deferred tax assets, net of current portion	6.1	8.6
Other non-current assets	0.8	1.8
Total assets	774.6	794.7
Current liabilities:	'	'
Accounts payable	51.8	63.3
Accrued liabilities	65.3	73.5
Current portion of long-term debt	0	5.3
Current portion of plant closure provisions	4.1	6.2
Current portion of unrecognized tax benefits	0	6.8
Current portion of deferred tax liabilities	0	0.2
Current portion of deferred income	0.2	0.3
Total current liabilities	121.4	155.6
Long-term debt, net of current portion	115	142.7
Plant closure provisions, net of current portion	27.4	26.2
Unrecognized tax benefits, net of current portion	5.9	6.2
Deferred tax liabilities, net of current portion	10.8	9.5
Pension liabilities	29.2	39
Acquisition-related contingent consideration	4.9	4.6
Other non-current liabilities	1.5	0.3
Deferred income, net of current portion	1	1.2
Total liabilities	317.1	385.3
Stockholders' 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	310.5	308.8
Treasury stock (5,126,216 and 5,207,947 shares at cost, respectively)	-72.8	-73.3
Retained earnings	377.1	327.5
Accumulated other comprehensive loss	-157.6	-153.9
Total stockholders' equity	457.5	409.4
Total liabilities and stockholders' equity	$774.60	$794.70

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowances for doubtful accounts	$4.40	$2
Inventory allowances	$9.70	$9.50
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	5,126,216	5,207,947

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Cash Flows from Operating Activities	'		'
Net income	$56.20		$49.10
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Depreciation and amortization	21.1	[1]	13.4	[1]
Impairment of Octane Additives segment goodwill	0		1
Deferred taxes	1.9		0.9
Repayment of promissory note in civil complaint settlement	-5		-5
Excess tax benefit from stock-based payment arrangements	-0.7		-2.9
Cash contributions to defined benefit pension plans	-8.8		-8.1
Non-cash expense of defined benefit pension plans	3		2.6
Stock option compensation	1.7		1.9
Changes in assets and liabilities, net of effects of acquired and divested companies:	'		'
Trade and other accounts receivable	17.4		7.2
Inventories	-14.8		-24.5
Prepaid expenses	2		-2.2
Accounts payable and accrued liabilities	-20		3.9
Accrued income taxes	10.7		-5.3
Plant closure provisions	-0.7		0.6
Unrecognized tax benefits	-7.2		-0.3
Other non-current assets and liabilities	2.2		-0.5
Net cash provided by operating activities	59		31.8
Cash Flows from Investing Activities	'		'
Capital expenditures	-9.5		-6.6
Business combinations, net of cash acquired	0.3		-50.6
Internally developed software and other costs	-6.1		-9
Proceeds on disposal of property, plant and equipment	0.2		0.1
Purchase of short-term investments	-4.2		-5.3
Sale of short-term investments	5.8		4.1
Net cash provided by/(used in) investing activities	-13.5		-67.3
Cash Flows from Financing Activities	'		'
Proceeds from revolving credit facility	8		86
Repayments of revolving credit facility	-35		-18
Repayments of term loans	-0.9		0
Refinancing costs	-0.1		-0.7
Excess tax benefit from stock-based payment arrangements	0.7		2.9
Dividend paid	-6.6		0
Issue of treasury stock	0.4		0.7
Repurchase of common stock	-0.9		-3.7
Net cash provided by/(used in) financing activities	-34.4		67.2
Effect of foreign currency exchange rate changes on cash	-0.9		-0.2
Net change in cash and cash equivalents	10.2		31.5
Cash and cash equivalents at beginning of period	80.2		22.4
Cash and cash equivalents at end of period	$90.40		$53.90
[1]	Amortization of deferred finance costs of $0.5 million (2013 - $0.3 million) are included in depreciation and amortization in the cash flow statement but in interest expense in the income statement.

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (Parenthetical) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Statement of Cash Flows [Abstract]	'	'
Amortization of deferred finance costs	$0.50	$0.30

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
In Millions
Beginning Balance at Dec. 31, 2013	$409.40	$0.30	$308.80	($73.30)	$327.50	($153.90)
Net income	56.2	'	'	'	56.2	'
Dividend paid ($0.27 per share)	-6.6	'	'	'	-6.6	'
Changes in cumulative translation adjustment	-6.2	'	'	'	'	-6.2
Treasury stock re-issued	0.7	'	-0.7	1.4	'	'
Treasury stock repurchased	-0.9	'	'	-0.9	'	'
Excess tax benefit from stock-based payment arrangements	0.7	'	0.7	'	'	'
Stock option compensation	1.7	'	1.7	'	'	'
Amortization of prior service credit, net of tax	-0.8	'	'	'	'	-0.8
Amortization of actuarial net losses, net of tax	3.3	'	'	'	'	3.3
Ending Balance at Sep. 30, 2014	$457.50	$0.30	$310.50	($72.80)	$377.10	($157.60)

Consolidated_Statement_of_Stoc1

Consolidated Statement of Stockholders' Equity (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2014
Statement of Stockholders' Equity [Abstract]	'
Dividend paid per share	$0.27

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Accounting Policies [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 13, 2014.
	The results for the interim period covered by this report are not necessarily indicative of the results to be expected for the full year.
	We have reclassified certain prior period amounts to conform to the current period presentation.
	When we use the terms the “Corporation,” “Company,” “Registrant,” “we,” “us” and “our,” we are referring to Innospec Inc. and its consolidated subsidiaries (“Innospec”) unless otherwise indicated or the context otherwise requires.

Segmental_Reporting

Segmental Reporting	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segmental Reporting	'
	NOTE 2 – SEGMENTAL 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 continues to decline as expected as our one remaining 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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Net sales:
	Fuel Specialties	$	156.1		$	137.4		$	465.4		$	403.6
	Performance Chemicals		57			47.9			172.5			140.2
	Octane Additives		15.1			7.5			32.3			33.4
		$	228.2		$	192.8		$	670.2		$	577.2
	Gross profit:
	Fuel Specialties	$	53.2		$	42.6		$	149.1		$	130.1
	Performance Chemicals		13.7			11.1			42.6			32.9
	Octane Additives		6.7			3.7			16.2			17.6
		$	73.6		$	57.4		$	207.9		$	180.6
	Operating income:
	Fuel Specialties	$	24.5		$	22.3		$	67.8		$	66.4
	Performance Chemicals		6.6			5.6			20.9			17.1
	Octane Additives		4.9			2.1			12			13
	Pension charge		(0.8	)		(0.7	)		(2.5	)		(2.1	)
	Corporate costs		(10.0	)		(9.4	)		(29.7	)		(29.4	)
	Impairment of Octane Additives segment goodwill		0			(0.4	)		0			(1.0	)
	Total operating income	$	25.2		$	19.5		$	68.5		$	64
	Restructuring charges separately disclosed in prior periods have been reclassified to corporate costs. We have reclassified the prior period amounts to conform to the current period presentation.
	The pension charge 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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Depreciation:
	Fuel Specialties	$	1		$	0.5		$	3.2		$	1.7
	Performance Chemicals		0.9			0.9			2.8			2.6
	Octane Additives		0.1			0.1			0.3			0.5
	Corporate		0.5			0.6			1.6			1.7
		$	2.5		$	2.1		$	7.9		$	6.5
	Amortization:
	Fuel Specialties	$	1.9		$	1.6		$	6.2		$	4.8
	Performance Chemicals		1.1			0.6			3.7			1.3
	Octane Additives		0			0.2			0			0.5
	Corporate		0.9			0			2.8			0
		$	3.9		$	2.4		$	12.7		$	6.6

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
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				Nine Months Ended
		September 30				September 30
		2014		2013		2014		2013
	Numerator (in millions):
	Net income available to common stockholders	$	20.8	$	14	$	56.2	$	49.1
	Denominator (in thousands):
	Weighted average common shares outstanding		24,420		23,621		24,394		23,518
	Dilutive effect of stock options and awards		495		475		455		567
	Denominator for diluted earnings per share		24,915		24,096		24,849		24,085
	Net income per share, basic:	$	0.85	$	0.59	$	2.3	$	2.09
	Net income per share, diluted:	$	0.83	$	0.58	$	2.26	$	2.04
	In the three and nine months ended September 30, 2014, the average number of anti-dilutive options excluded from the calculation of diluted earnings per share were 36,775 and 8,049, respectively. In the three and nine months ended September 30, 2013, the average number of anti-dilutive options excluded from the calculation of diluted earnings per share were nil and nil, respectively.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	NOTE 4 – GOODWILL
	The following table summarizes the goodwill movement year on year:
			Nine Months Ended
			September 30
	(in millions)		2014			2013
	At January 1:
	Gross cost (1)		$	424.4		$	384.2
	Accumulated impairment losses			(236.5	)		(235.2	)
	Net book amount		$	187.9		$	149
	Exchange effect			(0.3	)		(0.1	)
	Acquisitions			0			17
	Adjustments to purchase price allocation			0.3			0.4
	Impairment losses			0			(1.0	)
	At September 30:
	Gross cost (1)		$	424.4		$	401.5
	Accumulated impairment losses			(236.5	)		(236.2	)
	Net book amount		$	187.9		$	165.3
	(1)	Gross cost for 2014 and 2013 is net of $298.5 million of historical accumulated amortization.
	The Bachman Group Companies Acquisition
	On November 4, 2013, the Company acquired 100% of the voting equity interests in Bachman Services, Inc., Specialty Intermediates, Inc., Bachman Production Specialties, Inc. and Bachman Drilling & Production Specialties, Inc. (collectively “Bachman”). Bachman provide chemicals and services to the oil and gas industry and are based in Oklahoma City, Oklahoma. We purchased Bachman for a cash consideration of $45.8 million and by the issuance of 319,953 shares of unregistered Innospec Inc. common stock to the previous owners with a fair value of approximately $15 million, based on the Innospec share price on the closing date. We acquired the businesses in order to move us towards critical mass, and bring both good technology and market positioning in the oilfield specialties sector which forms part of our Fuel Specialties segment.
	The following table summarizes the calculations of the total purchase price and the allocation of the purchase price to the assets acquired and liabilities assumed for Bachman:
	(in millions)		Bachman
	Other intangible assets		$	25.9
	Goodwill			23.2
	Deferred tax on intangibles			(7.6	)
	Other net assets acquired, excluding cash of $2.0 million			17
	Purchase price, net of cash acquired		$	58.5
	In the second quarter of 2014, a $0.3 million reduction in the purchase price was agreed with the previous owners of Bachman in respect of post-closing working capital adjustments, resulting in a corresponding reduction in other net assets acquired. Also in the second quarter of 2014, we finalized the calculations of the fair values of assets acquired and liabilities assumed in the acquisition of Bachman, resulting in a further $0.3 million reduction in other net assets and a corresponding increase in goodwill.
	Bachman, and the associated goodwill, are included within our Fuel Specialties segment for management and reporting purposes.

Other_Intangible_Assets

Other Intangible Assets	9 Months Ended
	Sep. 30, 2014
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:
		Nine Months Ended
		September 30
	(in millions)	2014			2013
	Gross cost at January 1	$	175.5		$	106.2
	Capitalization of internally developed software and other costs		6.1			9
	Acquisitions		0			33.7
	Exchange effect		0			0.1
	Gross cost at September 30		181.6			149
	Accumulated amortization at January 1		(48.7	)		(37.6	)
	Amortization expense		(12.7	)		(6.6	)
	Exchange effect		0			0
	Accumulated amortization at September 30		(61.4	)		(44.2	)
	Net book amount at September 30	$	120.2		$	104.8
	Capitalization of internally developed software and other costs
	We are continuing with the implementation of a new, company-wide, information system platform. At September 30, 2014, we had capitalized $25.6 million (2013 – $19.1 million) in relation to this internally developed software.
	Amortization expense
		Nine Months Ended
		September 30
	(in millions)	2014			2013
	Product rights	$	(2.8	)	$	(0.3	)
	Brand names		(0.4	)		0
	Technology		(1.7	)		(1.5	)
	Customer relationships		(3.5	)		(2.7	)
	Patents		(0.2	)		(0.3	)
	Internally developed software		(2.8	)		0
	Non-compete agreements		(0.6	)		(0.6	)
	Marketing related		(0.7	)		(1.2	)
	Total	$	(12.7	)	$	(6.6	)

Pension_Plans

Pension Plans	9 Months Ended
	Sep. 30, 2014
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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Plan net pension credit/(charge):
	Service cost	$	(0.5	)	$	(0.4	)	$	(1.3	)	$	(1.2	)
	Interest cost on projected benefit obligation		(8.9	)		(7.6	)		(26.4	)		(23.2	)
	Expected return on plan assets		9.6			8.7			28.3			26.4
	Amortization of prior service credit		0.3			0.3			1			0.9
	Amortization of actuarial net losses		(1.3	)		(1.7	)		(4.1	)		(5.0	)
		$	(0.8	)	$	(0.7	)	$	(2.5	)	$	(2.1	)
	The amortization of prior service credit and actuarial net losses is a reclassification out of accumulated other comprehensive income/(loss) into selling, general and administrative expenses.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
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)	Interest and			Unrecognized			Total
		Penalties			Tax Benefits
	Opening balance at January 1, 2014	$	1.1		$	11.9		$	13
	Reductions for tax positions of prior periods		(0.4	)		(3.6	)		(4.0	)
	Reductions due to lapsed statute of limitations		(0.2	)		(2.9	)		(3.1	)
	Closing balance at September 30, 2014		0.5			5.4			5.9
	Current		0			0			0
	Non-current	$	0.5		$	5.4		$	5.9
	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. As previously disclosed, as at December 31, 2013, the Company and its U.S. subsidiaries were subject to tax audits in the U.S.. On March 6, 2014, the federal income tax examination by the IRS for 2009 was effectively settled. The additional tax cost was nominal and resulted in a reduction of $3.6 million in unrecognized tax benefits and a reduction of $0.4 million in associated interest and penalties in the first quarter of 2014.
	The Company and its U.S. subsidiaries remain open to examination by the IRS for years 2011 onwards. The Company’s subsidiaries in foreign tax jurisdictions are open to examination including France (2012 onwards), Germany (2010 onwards), Switzerland (2012 onwards) and the United Kingdom (2012 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, 2013 was approximately $605 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 practical at this time.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	NOTE 8 – LONG-TERM DEBT
	Long-term debt consists of the following:
	(in millions)	September 30,		December 31,
		2014		2013
	Revolving credit facility	$	115	$	142
	Promissory note		0		5
	Other long-term debt		0		1
			115		148
	Less current portion		0		(5.3	)
		$	115	$	142.7
	On July 31, 2014 the Company increased its borrowing capacity by $20 million such that its credit facility now provides for borrowings by us of up to $200 million until it expires on December 14, 2016 and may be drawn down in full in the U.S..

Plant_Closure_Provisions

Plant Closure Provisions	9 Months Ended
	Sep. 30, 2014
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:
		Nine Months Ended September 30
		2014									2013
	(in millions)	Severance			Remediation			Total			Total
	Total at January 1	$	1		$	31.4		$	32.4		$	30.4
	Charge for the period		0			2.1			2.1			2
	Utilized in the period		0			(1.8	)		(1.8	)		(1.4	)
	Released in the period		(1.0	)		0			(1.0	)		0
	Exchange effect		0			(0.2	)		(0.2	)		0.1
	Total at September 30		0			31.5			31.5			31.1
	Due within one year		0			(4.1	)		(4.1	)		(3.7	)
	Due after one year	$	0		$	27.4		$	27.4		$	27.4
	Amounts due within one year refer to provisions where expenditure is expected to arise within one year of the balance sheet date. A severance provision which is no longer required has been released to the income statement in the second quarter of 2014. Remediation costs are recognized in cost of goods sold.
	Remediation
	The remediation provision represents the Company’s liability for environmental liabilities and asset retirement obligations. The charge for the period represents the accretion expense recognized in the first nine months of 2014.
	We recognize environmental liabilities when they are probable and costs can be reasonably estimated, and asset retirement obligations when there is a legal obligation and costs can be reasonably estimated. The Company has to anticipate the program of work required and the associated future expected costs, and comply with environmental legislation in the countries in which it operates or has operated in. The Company views the costs of vacating our Ellesmere Port site as contingent upon if and when it vacates the site because there is no present intention to do so. The Company has further determined that, due to the uncertain product life of TEL particularly in the market for aviation gasoline and other products being manufactured on the site, there are uncertainties as to the probability and timing of the expected costs. Such uncertainties have been considered in estimating the provision.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	NOTE 10 – FAIR VALUE MEASUREMENTS
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The Company utilizes a mid-market pricing convention for valuing the majority of its assets and liabilities measured and reported at fair value. The Company utilizes market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. The Company primarily applies the market approach for recurring fair value measurements and endeavors to utilize the best available information. Accordingly, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The Company is able to classify fair value balances based on the observability of those inputs. The Company gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. In the first nine months of 2014, the Company evaluated the fair value hierarchy levels assigned to its assets and liabilities, and concluded that there should be no transfers into or out of Levels 1, 2 and 3.
	The following table presents the carrying amount and fair values of the Company’s assets and liabilities measured on a recurring basis:
		September 30, 2014				December 31, 2013
	(in millions)	Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	Assets
	Non-derivatives:
	Cash and cash equivalents	$	90.4	$	90.4	$	80.2	$	80.2
	Short-term investments		4.9		4.9		6.6		6.6
	Derivatives (Level 1 measurement):
	Other non-current assets:
	Foreign currency forward exchange contracts		0		0		1		1
	Liabilities
	Non-derivatives:
	Long-term debt (including current portion)	$	115	$	115	$	148	$	148
	Derivatives (Level 1 measurement):
	Other non-current liabilities:
	Foreign currency forward exchange contracts		1.3		1.3		0		0
	Non-financial liabilities (Level 3 measurement):
	Stock equivalent units		5.6		5.6		12.1		12.1
	Acquisition-related contingent consideration		4.9		4.9		4.6		4.6
	Foreign currency forward exchange contracts primarily relate to contracts entered into to hedge future known transactions or hedge balance sheet net cash positions. The movements in the carrying amounts and fair values of these contracts are largely due to changes in exchange rates against the U.S. dollar.

Derivative_Instruments_and_Ris

Derivative Instruments and Risk Management	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Risk Management	'
	NOTE 11 – DERIVATIVE INSTRUMENTS AND RISK MANAGEMENT
	The Company has limited involvement with derivative instruments and does not trade them. The Company does use derivatives to manage certain interest rate, foreign currency exchange rate and raw material cost exposures, as the need arises. As at September 30, 2014 and December 31, 2013 the Company did not hold any interest rate or raw material derivatives.
	The Company enters into various foreign currency forward exchange contracts to minimize currency exchange rate exposure from expected future cash flows. As at September 30, 2014 the contracts have maturity dates of up to eighteen 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 nine months of 2014 was a gain of $2.0 million.
	The Company sells a range of Fuel Specialties, Performance Chemicals and Octane Additives products to major oil refineries, oil & gas exploration and production companies and chemical companies throughout the world. Credit limits, ongoing credit evaluation and account monitoring procedures are intended to minimize bad debt risk. Collateral is not generally required.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	NOTE 12 – COMMITMENTS AND CONTINGENCIES
	Jalal Bezee Mejel Al-Gaood & Partner litigation
	On September 19, 2012, a claim was filed in the High Court of Justice in the United Kingdom by Jalal Bezee Mejel Al-Gaood & Partner and Future Agencies Company Limited (collectively “JAG”) against the Company, Innospec Limited and a former employee of Innospec Limited. JAG was the former Iraq distributor for Afton Chemicals Limited, a subsidiary of NewMarket Corporation, from at least 2005 until termination of that relationship in 2011. The stated claim, inclusive of costs and expenses, was for up to $42.3 million and relates to alleged loss of profits for JAG’s business in Iraq between 2004 and 2010. The Company has always believed the allegations in the claim were without merit and has defended vigorously its interests. On October 8, 2014, the judge dismissed the Claimant’s case in its entirety. The judgment also allows Innospec to bring a claim for reimbursement of its legal expenses.
	Other 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 other 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 September 30, 2014, such guarantees which are not recognized as liabilities in the consolidated financial statements amounted to $6.4 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.

Stockholders_Equity_and_StockB

Stockholders' Equity and Stock-Based Compensation Plans	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stockholders' Equity and Stock-Based Compensation Plans	'
	NOTE 13 – STOCKHOLDERS’ EQUITY AND STOCK-BASED COMPENSATION PLANS
	At September 30, 2014, the Company had authorized common stock of 40,000,000 shares (December 31, 2013 – 40,000,000). Issued shares at September 30, 2014, were 29,554,500 (December 31, 2013 – 29,554,500) and treasury stock amounted to 5,126,216 shares (December 31, 2013 – 5,207,947).
	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 Company has four active stock option plans, two of which provide for the grant of stock options to employees and one provides for the grant of stock options to non-employee directors. The fourth plan is a savings plan which provides for the grant of stock options to all Company employees provided they commit to make regular savings over a pre-defined period which can then be used to purchase common stock upon vesting of the options. The stock options have discrete vesting periods which range from 24 months to 6 years and in all cases stock options granted expire within 10 years of the date of grant. All grants are at the sole discretion of the Compensation Committee of the Board of Directors. Grants may be priced at market value or at a premium or discount (including at no cost). The aggregate number of shares of common stock reserved for issuance which can be granted under the plans is 2,640,000.
	The following table summarizes the transactions of the Company’s stock option plans for the nine months ended September 30, 2014:
		Number of			Weighted		Weighted
		Options			Average		Average
					Exercise		Grant-Date
					Price		Fair Value
	Outstanding at December 31, 2013		447,390		$	7.33
	Granted - at discount		370,925		$	28.14	$	13.88
	- at market value		21,542		$	46.03	$	14.18
	Exercised		(102,682	)	$	4.5
	Forfeited		(11,652	)	$	7.19
	Outstanding at September 30, 2014		725,523		$	19.52
	At September 30, 2014, there were 135,621 stock options that were exercisable, of which 51,001 had performance conditions attached.
	The Company’s policy is to issue shares from treasury stock to holders of stock options who exercise those options, but if sufficient treasury stock is not available, the Company will issue previously unissued shares of stock to holders of stock options who exercise options.
	The stock option compensation cost for the first nine months of 2014 was $1.7 million (2013 – $1.9 million). The total intrinsic value of options exercised in the first nine months of 2014 was $0.9 million (2013 – $3.2 million).
	The total compensation cost related to non-vested stock options not yet recognized at September 30, 2014 was $5.3 million and this cost is expected to be recognized over the weighted-average period of 2.46 years.
	Stock equivalent units
	SEUs have discrete vesting periods which range from 11 months to 4 years and in all cases SEUs granted expire within 10 years of the date of grant. Grants may be priced at market value or at a premium or discount (including at no cost). There is no limit to the number of SEUs that can be granted. The liability for SEUs is located in accrued liabilities in the consolidated balance sheets until they are cash settled.
	The following table summarizes the transactions of the Company’s SEUs for the nine months ended September 30, 2014:
		Number			Weighted		Weighted
		of SEUs			Average		Average
					Exercise		Grant-Date
					Price		Fair Value
	Outstanding at December 31, 2013		403,262		$	3.64
	Granted - at discount		50,713		$	0	$	33.33
	- at market value		7,147		$	46.03	$	14.18
	Exercised		(164,717	)	$	4.86
	Forfeited		(6,442	)	$	7.02
	Outstanding at September 30, 2014		289,963		$	3.37
	At September 30, 2014 there were 95,526 SEUs that are exercisable, of which 84,267 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 nine months of 2014 was $0.3 million (2013—$6.3 million). The total intrinsic value of SEUs exercised in the first nine months of 2014 was $3.5 million (2013 – $2.1 million).
	The weighted-average remaining vesting period of non-vested SEUs is 1.63 years.
	Additional exceptional long-term incentive plan
	In the first quarter of 2014, Innospec implemented an additional exceptional long-term incentive plan to reward selected executives with a cash bonus for delivering exceptional performance. One of the elements of the plan is payable only if the Innospec share performance matches or out-performs that of competitors, as measured by the Russell 2000 Index, over the performance period January 1, 2014 to December 31, 2016. The maximum cash bonus payable under this element of the plan is $3 million and is accounted for as share-based compensation. As such, the fair value of these liability cash-settled long-term incentives is calculated on a quarterly basis. The fair value is calculated using a Monte Carlo model and is summarized as follows:
	(in millions)	2014
	Balance at January 1	$	0
	Compensation charge for the period		0.1
	Balance at September 30	$	0.1
	The following assumptions were used in the Monte Carlo model at September 30, 2014:
		2014
	Dividend yield		1.45	%
	Volatility of Innospec’s share price		28.96	%
	Risk free interest rate		1.07	%

Reclassifications_Out_of_Accum

Reclassifications Out of Accumulated Other Comprehensive Income/(Loss)	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Reclassifications Out of Accumulated Other Comprehensive Income/(Loss)	'
	NOTE 14 – RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)
	Reclassifications out of accumulated other comprehensive loss for the first nine months of 2014 were:
	(in millions)		Amount			Affected Line Item in the
			Reclassified			Statement where Net
	Details about AOCL Components		from AOCL			Income is Presented
	Defined benefit pension plan items:
	Amortization of prior service credit		$	(1.0	)	See (1) below
	Amortization of actuarial net losses			4.1		See (1) below
				3.1		Total before tax
				(0.6	)	Income tax expense
				2.5		Net of tax
	Total reclassifications		$	2.5		Net of tax
	(1)	These items are included in the computation of net periodic pension cost. See Note 6 for additional information.
	Changes in accumulated other comprehensive loss for the first nine months of 2014, net of tax, were:
	(in millions)		Defined			Cumulative			Total
			Benefit			Translation
			Pension Plan			Adjustments
			Items
	Balance at December 31, 2013		$	(120.2	)	$	(33.7	)	$	(153.9	)
	Other comprehensive income/(loss) before reclassifications			0			(6.2	)		(6.2	)
	Amounts reclassified from AOCL			2.5			0			2.5
	Total other comprehensive income/(loss)			2.5			(6.2	)		(3.7	)
	Balance at September 30, 2014		$	(117.7	)	$	(39.9	)	$	(157.6	)

Recently_Issued_Accounting_Pro

Recently Issued Accounting Pronouncements	9 Months Ended
	Sep. 30, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recently Issued Accounting Pronouncements	'
	NOTE 15 – RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. ASU 2014-09 is effective for annual periods, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.
	In July 2013, the FASB issued ASU 2013-11, Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (“ASU 2013-11”), which requires an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, similar tax loss, or a tax credit carryforward. To the extent the tax benefit is not available at the reporting date under the governing tax law or if the entity does not intend to use the deferred tax asset for such purpose, the unrecognized tax benefit should be presented as a liability and not combined with deferred tax assets. ASU 2013-11 is effective for annual periods, and interim periods within those years, beginning after December 15, 2013. The amendments are to be applied to all unrecognized tax benefits that exist as of the effective date and may be applied retrospectively to each prior reporting period presented. The implementation of the amended accounting guidance has not had a material impact on our consolidated financial statements.

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2014
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 nine months of 2014 the Company incurred fees from SGR of $0.8 million (2013 – $0.9 million). As at September 30, 2014, the amount due to SGR from the Company was $0.5 million (December 31, 2013 - $0.2 million).

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	NOTE 17 – SUBSEQUENT EVENTS
	On October 27, 2014, the Company acquired 100% of the membership interests in Independence Oilfield Chemicals LLC (“Independence”). Independence, based in Houston Texas, services the oil and gas industry, with a focus on completion, stimulation and production chemicals. We purchased Independence for a total discounted consideration of $212.8 million, with an initial payment at closing of $99.0 million funded from existing cash and debt facilities. Innospec will make two deferred consideration payments, with the first one payable approximately one year after closing, and the second one payable approximately two years after closing, with a portion of such deferred payments payable, at Innospec’s election, in shares of Innospec’s common stock. We acquired the business in order to move forward our strategy of building a new market leader in the oilfield specialties sector which forms part of our Fuel Specialties segment.
	At the time of filing our September 30, 2014 Form 10-Q, we are unable to provide supplemental pro forma information due to the timing of the acquisition being completed.
	The following table summarizes the estimated allocation of the purchase price to the assets acquired and liabilities assumed for Independence. The purchase price allocation is not yet complete as we are in the process of finalising the valuation of the assets acquired. Final determination of the fair values may result in adjustments to the amounts presented below:
	(in millions)
	Other intangible assets	$	78.7
	Goodwill		115.8
	Other net assets acquired		18.3
	Purchase price	$	212.8

Recently_Issued_Accounting_Pro1

Recently Issued Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Changes and Error Corrections [Abstract]	'
Revenue from Contracts with Customers	'
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. ASU 2014-09 is effective for annual periods, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.
Presentation of an Unrecognized Tax Benefit	'
	In July 2013, the FASB issued ASU 2013-11, Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (“ASU 2013-11”), which requires an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, similar tax loss, or a tax credit carryforward. To the extent the tax benefit is not available at the reporting date under the governing tax law or if the entity does not intend to use the deferred tax asset for such purpose, the unrecognized tax benefit should be presented as a liability and not combined with deferred tax assets. ASU 2013-11 is effective for annual periods, and interim periods within those years, beginning after December 15, 2013. The amendments are to be applied to all unrecognized tax benefits that exist as of the effective date and may be applied retrospectively to each prior reporting period presented. The implementation of the amended accounting guidance has not had a material impact on our consolidated financial statements.

Segmental_Reporting_Tables

Segmental Reporting (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segmental Reporting	'
	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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Net sales:
	Fuel Specialties	$	156.1		$	137.4		$	465.4		$	403.6
	Performance Chemicals		57			47.9			172.5			140.2
	Octane Additives		15.1			7.5			32.3			33.4
		$	228.2		$	192.8		$	670.2		$	577.2
	Gross profit:
	Fuel Specialties	$	53.2		$	42.6		$	149.1		$	130.1
	Performance Chemicals		13.7			11.1			42.6			32.9
	Octane Additives		6.7			3.7			16.2			17.6
		$	73.6		$	57.4		$	207.9		$	180.6
	Operating income:
	Fuel Specialties	$	24.5		$	22.3		$	67.8		$	66.4
	Performance Chemicals		6.6			5.6			20.9			17.1
	Octane Additives		4.9			2.1			12			13
	Pension charge		(0.8	)		(0.7	)		(2.5	)		(2.1	)
	Corporate costs		(10.0	)		(9.4	)		(29.7	)		(29.4	)
	Impairment of Octane Additives segment goodwill		0			(0.4	)		0			(1.0	)
	Total operating income	$	25.2		$	19.5		$	68.5		$	64
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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Depreciation:
	Fuel Specialties	$	1		$	0.5		$	3.2		$	1.7
	Performance Chemicals		0.9			0.9			2.8			2.6
	Octane Additives		0.1			0.1			0.3			0.5
	Corporate		0.5			0.6			1.6			1.7
		$	2.5		$	2.1		$	7.9		$	6.5
	Amortization:
	Fuel Specialties	$	1.9		$	1.6		$	6.2		$	4.8
	Performance Chemicals		1.1			0.6			3.7			1.3
	Octane Additives		0			0.2			0			0.5
	Corporate		0.9			0			2.8			0
		$	3.9		$	2.4		$	12.7		$	6.6

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Summary of Earnings Per Share	'
	Per share amounts are computed as follows:
		Three Months Ended				Nine Months Ended
		September 30				September 30
		2014		2013		2014		2013
	Numerator (in millions):
	Net income available to common stockholders	$	20.8	$	14	$	56.2	$	49.1
	Denominator (in thousands):
	Weighted average common shares outstanding		24,420		23,621		24,394		23,518
	Dilutive effect of stock options and awards		495		475		455		567
	Denominator for diluted earnings per share		24,915		24,096		24,849		24,085
	Net income per share, basic:	$	0.85	$	0.59	$	2.3	$	2.09
	Net income per share, diluted:	$	0.83	$	0.58	$	2.26	$	2.04

Goodwill_Tables

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2014
Summary of Goodwill	'
	The following table summarizes the goodwill movement year on year:
			Nine Months Ended
			September 30
	(in millions)		2014			2013
	At January 1:
	Gross cost (1)		$	424.4		$	384.2
	Accumulated impairment losses			(236.5	)		(235.2	)
	Net book amount		$	187.9		$	149
	Exchange effect			(0.3	)		(0.1	)
	Acquisitions			0			17
	Adjustments to purchase price allocation			0.3			0.4
	Impairment losses			0			(1.0	)
	At September 30:
	Gross cost (1)		$	424.4		$	401.5
	Accumulated impairment losses			(236.5	)		(236.2	)
	Net book amount		$	187.9		$	165.3
	(1)	Gross cost for 2014 and 2013 is net of $298.5 million of historical accumulated amortization.
Bachman Group Companies [Member]	'
Purchase Price and Fair Values of Assets Acquired and Liabilities Assumed	'
	The following table summarizes the calculations of the total purchase price and the allocation of the purchase price to the assets acquired and liabilities assumed for Bachman:
	(in millions)		Bachman
	Other intangible assets		$	25.9
	Goodwill			23.2
	Deferred tax on intangibles			(7.6	)
	Other net assets acquired, excluding cash of $2.0 million			17
	Purchase price, net of cash acquired		$	58.5

Other_Intangible_Assets_Tables

Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Summary of Other Intangible Assets	'
	The following table summarizes the other intangible assets movement year on year:
		Nine Months Ended
		September 30
	(in millions)	2014			2013
	Gross cost at January 1	$	175.5		$	106.2
	Capitalization of internally developed software and other costs		6.1			9
	Acquisitions		0			33.7
	Exchange effect		0			0.1
	Gross cost at September 30		181.6			149
	Accumulated amortization at January 1		(48.7	)		(37.6	)
	Amortization expense		(12.7	)		(6.6	)
	Exchange effect		0			0
	Accumulated amortization at September 30		(61.4	)		(44.2	)
	Net book amount at September 30	$	120.2		$	104.8
Schedule of Amortization Expense	'
	Amortization expense
		Nine Months Ended
		September 30
	(in millions)	2014			2013
	Product rights	$	(2.8	)	$	(0.3	)
	Brand names		(0.4	)		0
	Technology		(1.7	)		(1.5	)
	Customer relationships		(3.5	)		(2.7	)
	Patents		(0.2	)		(0.3	)
	Internally developed software		(2.8	)		0
	Non-compete agreements		(0.6	)		(0.6	)
	Marketing related		(0.7	)		(1.2	)
	Total	$	(12.7	)	$	(6.6	)

Pension_Plans_Tables

Pension Plans (Tables)	9 Months Ended
	Sep. 30, 2014
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						Nine Months Ended
		September 30						September 30
	(in millions)	2014			2013			2014			2013
	Plan net pension credit/(charge):
	Service cost	$	(0.5	)	$	(0.4	)	$	(1.3	)	$	(1.2	)
	Interest cost on projected benefit obligation		(8.9	)		(7.6	)		(26.4	)		(23.2	)
	Expected return on plan assets		9.6			8.7			28.3			26.4
	Amortization of prior service credit		0.3			0.3			1			0.9
	Amortization of actuarial net losses		(1.3	)		(1.7	)		(4.1	)		(5.0	)
		$	(0.8	)	$	(0.7	)	$	(2.5	)	$	(2.1	)

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2014
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)	Interest and			Unrecognized			Total
		Penalties			Tax Benefits
	Opening balance at January 1, 2014	$	1.1		$	11.9		$	13
	Reductions for tax positions of prior periods		(0.4	)		(3.6	)		(4.0	)
	Reductions due to lapsed statute of limitations		(0.2	)		(2.9	)		(3.1	)
	Closing balance at September 30, 2014		0.5			5.4			5.9
	Current		0			0			0
	Non-current	$	0.5		$	5.4		$	5.9

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-Term Debt	'
	Long-term debt consists of the following:
	(in millions)	September 30,		December 31,
		2014		2013
	Revolving credit facility	$	115	$	142
	Promissory note		0		5
	Other long-term debt		0		1
			115		148
	Less current portion		0		(5.3	)
		$	115	$	142.7

Plant_Closure_Provisions_Table

Plant Closure Provisions (Tables)	9 Months Ended
	Sep. 30, 2014
Restructuring and Related Activities [Abstract]	'
Movements in Plant Closure and Restructuring Provisions	'
	Movements in the provisions are summarized as follows:
		Nine Months Ended September 30
		2014									2013
	(in millions)	Severance			Remediation			Total			Total
	Total at January 1	$	1		$	31.4		$	32.4		$	30.4
	Charge for the period		0			2.1			2.1			2
	Utilized in the period		0			(1.8	)		(1.8	)		(1.4	)
	Released in the period		(1.0	)		0			(1.0	)		0
	Exchange effect		0			(0.2	)		(0.2	)		0.1
	Total at September 30		0			31.5			31.5			31.1
	Due within one year		0			(4.1	)		(4.1	)		(3.7	)
	Due after one year	$	0		$	27.4		$	27.4		$	27.4

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
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:
		September 30, 2014				December 31, 2013
	(in millions)	Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value
	Assets
	Non-derivatives:
	Cash and cash equivalents	$	90.4	$	90.4	$	80.2	$	80.2
	Short-term investments		4.9		4.9		6.6		6.6
	Derivatives (Level 1 measurement):
	Other non-current assets:
	Foreign currency forward exchange contracts		0		0		1		1
	Liabilities
	Non-derivatives:
	Long-term debt (including current portion)	$	115	$	115	$	148	$	148
	Derivatives (Level 1 measurement):
	Other non-current liabilities:
	Foreign currency forward exchange contracts		1.3		1.3		0		0
	Non-financial liabilities (Level 3 measurement):
	Stock equivalent units		5.6		5.6		12.1		12.1
	Acquisition-related contingent consideration		4.9		4.9		4.6		4.6

Stockholders_Equity_and_StockB1

Stockholders' Equity and Stock-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Additional Exceptional Long-Term Incentive Plan [Member]	'
Fair Value of Liability Cash-Settled Stock Appreciation Rights	'
	The fair value is calculated using a Monte Carlo model and is summarized as follows:
	(in millions)	2014
	Balance at January 1	$	0
	Compensation charge for the period		0.1
	Balance at September 30	$	0.1
Assumptions Used in the Monte Carlo Model	'
	The following assumptions were used in the Monte Carlo model at September 30, 2014:
		2014
	Dividend yield		1.45	%
	Volatility of Innospec’s share price		28.96	%
	Risk free interest rate		1.07	%
Stock Options Plan [Member]	'
Summary of Transactions of the Company's Stock Option Plans	'
	The following table summarizes the transactions of the Company’s stock option plans for the nine months ended September 30, 2014:
		Number of			Weighted		Weighted
		Options			Average		Average
					Exercise		Grant-Date
					Price		Fair Value
	Outstanding at December 31, 2013		447,390		$	7.33
	Granted - at discount		370,925		$	28.14	$	13.88
	- at market value		21,542		$	46.03	$	14.18
	Exercised		(102,682	)	$	4.5
	Forfeited		(11,652	)	$	7.19
	Outstanding at September 30, 2014		725,523		$	19.52
Stock Equivalent Units [Member]	'
Summarizes Transactions of the SEUs	'
	The following table summarizes the transactions of the Company’s SEUs for the nine months ended September 30, 2014:
		Number			Weighted		Weighted
		of SEUs			Average		Average
					Exercise		Grant-Date
					Price		Fair Value
	Outstanding at December 31, 2013		403,262		$	3.64
	Granted - at discount		50,713		$	0	$	33.33
	- at market value		7,147		$	46.03	$	14.18
	Exercised		(164,717	)	$	4.86
	Forfeited		(6,442	)	$	7.02
	Outstanding at September 30, 2014		289,963		$	3.37

Reclassifications_Out_of_Accum1

Reclassifications Out of Accumulated Other Comprehensive Income/(Loss) (Tables)	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Summary of Reclassifications Out of Accumulated Other Comprehensive Loss	'
	Reclassifications out of accumulated other comprehensive loss for the first nine months of 2014 were:
	(in millions)		Amount			Affected Line Item in the
			Reclassified			Statement where Net
	Details about AOCL Components		from AOCL			Income is Presented
	Defined benefit pension plan items:
	Amortization of prior service credit		$	(1.0	)	See (1) below
	Amortization of actuarial net losses			4.1		See (1) below
				3.1		Total before tax
				(0.6	)	Income tax expense
				2.5		Net of tax
	Total reclassifications		$	2.5		Net of tax
	(1)	These items are included in the computation of net periodic pension cost. See Note 6 for additional information.
Changes in Accumulated Other Comprehensive Loss	'
	Changes in accumulated other comprehensive loss for the first nine months of 2014, net of tax, were:
	(in millions)		Defined			Cumulative			Total
			Benefit			Translation
			Pension Plan			Adjustments
			Items
	Balance at December 31, 2013		$	(120.2	)	$	(33.7	)	$	(153.9	)
	Other comprehensive income/(loss) before reclassifications			0			(6.2	)		(6.2	)
	Amounts reclassified from AOCL			2.5			0			2.5
	Total other comprehensive income/(loss)			2.5			(6.2	)		(3.7	)
	Balance at September 30, 2014		$	(117.7	)	$	(39.9	)	$	(157.6	)

Subsequent_Events_Tables

Subsequent Events (Tables)	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Estimated Allocation of Purchase Price to Assets Acquired and Liabilities Assumed	'
	The following table summarizes the estimated allocation of the purchase price to the assets acquired and liabilities assumed for Independence. The purchase price allocation is not yet complete as we are in the process of finalising the valuation of the assets acquired. Final determination of the fair values may result in adjustments to the amounts presented below:
	(in millions)
	Other intangible assets	$	78.7
	Goodwill		115.8
	Other net assets acquired		18.3
	Purchase price	$	212.8

Segmental_Reporting_Additional

Segmental Reporting - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2014
	Segment
Segment Reporting [Abstract]	'
Number of segments	3

Segmental_Reporting_Segment_Re

Segmental Reporting - Segment Reporting (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Net sales	$228.20	$192.80	$670.20	$577.20
Gross profit	73.6	57.4	207.9	180.6
Operating income	25.2	19.5	68.5	64
Pension charge	-0.8	-0.7	-2.5	-2.1
Impairment of Octane Additives segment goodwill	0	-0.4	0	-1
Operating Segments [Member] | Fuel Specialties [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Net sales	156.1	137.4	465.4	403.6
Gross profit	53.2	42.6	149.1	130.1
Operating income	24.5	22.3	67.8	66.4
Operating Segments [Member] | Performance Chemicals [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Net sales	57	47.9	172.5	140.2
Gross profit	13.7	11.1	42.6	32.9
Operating income	6.6	5.6	20.9	17.1
Operating Segments [Member] | Octane Additives [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Net sales	15.1	7.5	32.3	33.4
Gross profit	6.7	3.7	16.2	17.6
Operating income	4.9	2.1	12	13
Segment Reconciling Items [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Pension charge	-0.8	-0.7	-2.5	-2.1
Impairment of Octane Additives segment goodwill	0	-0.4	0	-1
Corporate, Non-Segment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Corporate costs	($10)	($9.40)	($29.70)	($29.40)

Segmental_Reporting_Summary_of

Segmental Reporting - Summary of Segment Depreciation and Amortization (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Summary of segment depreciation and amortization	'	'	'	'
Depreciation	$2.50	$2.10	$7.90	$6.50
Amortization	3.9	2.4	12.7	6.6
Operating Segments [Member] | Fuel Specialties [Member]	'	'	'	'
Summary of segment depreciation and amortization	'	'	'	'
Depreciation	1	0.5	3.2	1.7
Amortization	1.9	1.6	6.2	4.8
Operating Segments [Member] | Performance Chemicals [Member]	'	'	'	'
Summary of segment depreciation and amortization	'	'	'	'
Depreciation	0.9	0.9	2.8	2.6
Amortization	1.1	0.6	3.7	1.3
Operating Segments [Member] | Octane Additives [Member]	'	'	'	'
Summary of segment depreciation and amortization	'	'	'	'
Depreciation	0.1	0.1	0.3	0.5
Amortization	0	0.2	0	0.5
Corporate, Non-Segment [Member]	'	'	'	'
Summary of segment depreciation and amortization	'	'	'	'
Depreciation	0.5	0.6	1.6	1.7
Amortization	$0.90	$0	$2.80	$0

Earnings_Per_Share_Summary_of_

Earnings Per Share - Summary of Earnings Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator (in millions):	'	'	'	'
Net income available to common stockholders	$20.80	$14	$56.20	$49.10
Denominator (in thousands):	'	'	'	'
Weighted average common shares outstanding	24,420	23,621	24,394	23,518
Dilutive effect of stock options and awards	495	475	455	567
Denominator for diluted earnings per share	24,915	24,096	24,849	24,085
Net income per share, basic:	$0.85	$0.59	$2.30	$2.09
Net income per share, diluted:	$0.83	$0.58	$2.26	$2.04

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Average number of anti-dilutive options excluded from the calculation of diluted earnings per share	36,775	0	8,049	0

Goodwill_Summary_of_Goodwill_D

Goodwill - Summary of Goodwill (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'
At January 1, Gross cost	'	'	$424.40	$384.20
At January 1, Accumulated impairment losses	'	'	-236.5	-235.2
At January 1, Net book amount	'	'	187.9	149
Exchange effect	'	'	-0.3	-0.1
Acquisitions	'	'	0	17
Adjustments to purchase price allocation	'	'	0.3	0.4
Impairment losses	0	-0.4	0	-1
At September 30, Gross cost	424.4	401.5	424.4	401.5
At September 30, Accumulated impairment losses	-236.5	-236.2	-236.5	-236.2
At September 30, Net book amount	$187.90	$165.30	$187.90	$165.30

Goodwill_Summary_of_Goodwill_P

Goodwill - Summary of Goodwill (Parenthetical) (Detail) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Historical accumulated amortization	$298.50	$298.50

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (Bachman Group Companies [Member], USD $)	0 Months Ended	6 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 04, 2013	Jun. 30, 2014	Sep. 30, 2014	Nov. 04, 2013
Bachman Group Companies [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Voting equity interests acquired	'	'	'	100.00%
Purchase price of cash	$45.80	'	'	'
Issuance of common stock	319,953	'	'	'
Purchase price of common stock	15	'	'	'
Date of acquisition	'	'	4-Nov-13	'
Reduction in purchase price of post-closing working capital adjustments	'	0.3	'	'
Reduction in other net assets	'	$0.30	'	'

Goodwill_Purchase_Price_and_Fa

Goodwill - Purchase Price and Fair Values of Assets Acquired and Liabilities Assumed (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Business Acquisition [Line Items]	'	'	'	'
Goodwill	$187.90	$187.90	$165.30	$149
Bachman Group Companies [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Other intangible assets	25.9	'	'	'
Goodwill	23.2	'	'	'
Deferred tax on intangibles	-7.6	'	'	'
Other net assets acquired, excluding cash of $2.0 million	17	'	'	'
Purchase price, net of cash acquired	$58.50	'	'	'

Goodwill_Purchase_Price_and_Fa1

Goodwill - Purchase Price and Fair Values of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) (Bachman Group Companies [Member], USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Bachman Group Companies [Member]	'
Business Acquisition [Line Items]	'
Cash acquired	$2

Other_Intangible_Assets_Summar

Other Intangible Assets - Summary of Other Intangible Assets (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'	'
Gross cost at January 1	'	'	$175.50	$106.20	'
Capitalization of internally developed software and other costs	'	'	6.1	9	'
Acquisitions	'	'	0	33.7	'
Exchange effect	'	'	0	0.1	'
Gross cost at September 30	181.6	149	181.6	149	'
Accumulated amortization at January 1	'	'	-48.7	-37.6	'
Amortization expense	-3.9	-2.4	-12.7	-6.6	'
Exchange effect	'	'	0	0	'
Accumulated amortization at September 30	-61.4	-44.2	-61.4	-44.2	'
Net book amount at September 30	$120.20	$104.80	$120.20	$104.80	$126.80

Other_Intangible_Assets_Additi

Other Intangible Assets - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Intangible asset capitalized	$181.60	$175.50	$149	$106.20
Internally Developed Software [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Intangible asset capitalized	$25.60	'	$19.10	'

Other_Intangible_Assets_Schedu

Other Intangible Assets - Schedule of Amortization Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	($3.90)	($2.40)	($12.70)	($6.60)
Product Rights [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-2.8	-0.3
Brand Names [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-0.4	0
Technology [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-1.7	-1.5
Customer Relationships [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-3.5	-2.7
Patents [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-0.2	-0.3
Internally Developed Software [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-2.8	0
Non-Compete Agreements [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	-0.6	-0.6
Marketing Related [Member]	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense	'	'	($0.70)	($1.20)

Pension_Plans_Defined_Benefit_

Pension Plans - Defined Benefit Pension Plan (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Plan net pension credit/(charge):	'	'	'	'
Service cost	($0.50)	($0.40)	($1.30)	($1.20)
Interest cost on projected benefit obligation	-8.9	-7.6	-26.4	-23.2
Expected return on plan assets	9.6	8.7	28.3	26.4
Amortization of prior service credit	0.3	0.3	1	0.9
Amortization of actuarial net losses	-1.3	-1.7	-4.1	-5
Net pension charge	($0.80)	($0.70)	($2.50)	($2.10)

Income_Taxes_RollForward_of_Un

Income Taxes - Roll-Forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties (Detail) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Mar. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014
			Interest and Penalties [Member]	Interest and Penalties [Member]	Unrecognized Tax Benefits [Member]	Unrecognized Tax Benefits [Member]
Income Tax Contingency [Line Items]	'	'	'	'	'	'
Opening balance at January 1, 2014	$13	'	$1.10	$1.10	$11.90	$11.90
Reductions for tax positions of prior periods	-4	'	-0.4	-0.4	-3.6	-3.6
Reductions due to lapsed statute of limitations	-3.1	'	'	-0.2	'	-2.9
Closing balance at September 30, 2014	5.9	'	'	0.5	'	5.4
Current	0	6.8	'	0	'	0
Non-current	$5.90	$6.20	'	$0.50	'	$5.40

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	9 Months Ended	12 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Mar. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014
			Unrecognized Tax Benefits [Member]	Unrecognized Tax Benefits [Member]	Interest and Penalties [Member]	Interest and Penalties [Member]
Income Tax Contingency [Line Items]	'	'	'	'	'	'
Reductions for tax positions of prior periods	$4	'	$3.60	$3.60	$0.40	$0.40
Income tax examination, description	'The Company and its U.S. subsidiaries remain open to examination by the IRS for years 2011 onwards. The Companybs subsidiaries in foreign tax jurisdictions are open to examination including France (2012 onwards), Germany (2010 onwards), Switzerland (2012 onwards) and the United Kingdom (2012 onwards).	'	'	'	'	'
Unremitted earnings	'	$605	'	'	'	'

LongTerm_Debt_Schedule_of_Long

Long-Term Debt - Schedule of Long-Term Debt (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term debt	$115	$148
Less current portion	0	-5.3
Long-term debt, net of current portion	115	142.7
Revolving Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	115	142
Promissory Note [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	0	5
Other Long-Term Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	$0	$1

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended
	Jul. 31, 2014	Sep. 30, 2014	Jul. 31, 2014
Debt Disclosure [Abstract]	'	'	'
Borrowing amount through credit facility	'	'	$200,000,000
Expiration date of facility	'	14-Dec-16	'
Credit facility, borrowings capacity increased amount	$20,000,000	$20,000,000	'

Plant_Closure_Provisions_Movem

Plant Closure Provisions - Movements in Plant Closure and Restructuring Provisions (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]	'	'	'
Beginning Balance	$32.40	$30.40	'
Charge for the period	2.1	2	'
Utilized in the period	-1.8	-1.4	'
Released in the period	-1	0	'
Exchange effect	-0.2	0.1	'
Ending Balance	31.5	31.1	'
Due within one year	-4.1	-3.7	-6.2
Due after one year	27.4	27.4	26.2
Ending Balance	31.5	31.1	'
Severance [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Beginning Balance	1	'	'
Charge for the period	0	'	'
Utilized in the period	0	'	'
Released in the period	-1	'	'
Exchange effect	0	'	'
Ending Balance	0	'	'
Due within one year	0	'	'
Due after one year	0	'	'
Ending Balance	0	'	'
Remediation [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Beginning Balance	31.4	'	'
Charge for the period	2.1	'	'
Utilized in the period	-1.8	'	'
Released in the period	0	'	'
Exchange effect	-0.2	'	'
Ending Balance	31.5	'	'
Due within one year	-4.1	'	'
Due after one year	27.4	'	'
Ending Balance	$31.50	'	'

Fair_Value_Measurements_Carryi

Fair Value Measurements - Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Non-financial liabilities (Level 3 measurement):	'	'
Acquisition-related contingent consideration	$4.90	$4.60
Recurring [Member] | Carrying Amount [Member]	'	'
Non-derivatives:	'	'
Cash and cash equivalents	90.4	80.2
Short-term investments	4.9	6.6
Non-derivatives:	'	'
Long-term debt (including current portion)	115	148
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	1
Derivatives (Level 1 measurement):	'	'
Foreign currency forward exchange contracts	1.3	0
Recurring [Member] | Carrying Amount [Member] | Non-financial Assets and Liabilities (Level 3 Measurement) [Member]	'	'
Non-financial liabilities (Level 3 measurement):	'	'
Stock equivalent units	5.6	12.1
Acquisition-related contingent consideration	4.9	4.6
Recurring [Member] | Fair Value [Member]	'	'
Non-derivatives:	'	'
Cash and cash equivalents	90.4	80.2
Short-term investments	4.9	6.6
Non-derivatives:	'	'
Long-term debt (including current portion)	115	148
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	1
Derivatives (Level 1 measurement):	'	'
Foreign currency forward exchange contracts	1.3	0
Recurring [Member] | Fair Value [Member] | Non-financial Assets and Liabilities (Level 3 Measurement) [Member]	'	'
Non-financial liabilities (Level 3 measurement):	'	'
Stock equivalent units	5.6	12.1
Acquisition-related contingent consideration	$4.90	$4.60

Derivative_Instruments_and_Ris1

Derivative Instruments and Risk Management - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Derivative [Line Items]	'
Maturity period of foreign currency forward exchange contracts	'18 months
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Exchange Contracts [Member] | Other Income/(Expense) [Member]	'
Derivative [Line Items]	'
Amount of Gain Recognized in Income	2

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Sep. 19, 2012	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'	'
Stated claim inclusive of costs and expenses	$42.30	'
Guarantees	'	$6.40

Stockholders_Equity_and_StockB2

Stockholders' Equity and Stock-Based Compensation Plans - Additional Information (Detail) (USD $)	9 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014
			Stock Options Plan [Member]	Stock Options Plan [Member]	Stock Options Plan [Member]	Stock Options Plan [Member]	Stock Equivalent Units [Member]	Stock Equivalent Units [Member]	Stock Equivalent Units [Member]	Stock Equivalent Units [Member]
			Stock_Plan		Minimum [Member]	Maximum [Member]			Minimum [Member]	Maximum [Member]
			Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'
Common stock, shares authorized	40,000,000	40,000,000	'	'	'	'	'	'	'	'
Number of shares issued	29,554,500	29,554,500	'	'	'	'	'	'	'	'
Treasury stock, shares	5,126,216	5,207,947	'	'	'	'	'	'	'	'
Number of active stock option plans	'	'	4	'	'	'	'	'	'	'
Number of active stock option plans for employees	'	'	2	'	'	'	'	'	'	'
Number of active stock option plans for non-employee directors	'	'	1	'	'	'	'	'	'	'
Range of stock vesting period	'	'	'	'	'24 months	'6 years	'	'	'11 months	'4 years
Expiration term for stock granted	'	'	'10 years	'	'	'	'10 years	'	'	'
Aggregate number of shares of common stock reserved for issuance which can be granted	'	'	2,640,000	'	'	'	'	'	'	'
Number of stock options exercisable and fully vested	'	'	135,621	'	'	'	'	'	'	'
Fully vested stock options with performance conditions attached	'	'	51,001	'	'	'	84,267	'	'	'
Stock option compensation cost of SEUs	'	'	$1.70	$1.90	'	'	$0.30	$6.30	'	'
Total intrinsic value of options exercised	'	'	0.9	3.2	'	'	3.5	2.1	'	'
Total compensation cost related to non-vested stock options not yet recognized	'	'	5.3	'	'	'	'	'	'	'
Expected compensation cost recognized over the weighted-average period	'	'	'2 years 5 months 16 days	'	'	'	'1 year 7 months 17 days	'	'	'
Number of exercisable SEUs	'	'	'	'	'	'	95,526	'	'	'
Maximum cash bonus under long-term incentive plan	$3	'	'	'	'	'	'	'	'	'

Stockholders_Equity_and_StockB3

Stockholders' Equity and Stock-Based Compensation Plans - Summary of Transactions of the Company's Stock Option Plans (Detail) (Stock Options Plan [Member], USD $)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Outstanding, Number of Options, Beginning balance	447,390
Exercised, Number of Options	-102,682
Forfeited, Number of Options	-11,652
Outstanding, Number of Options, Ending balance	725,523
Outstanding, Weighted Average Exercise Price, Beginning balance	$7.33
Exercised, Weighted Average Exercise Price	$4.50
Forfeited, Weighted Average Exercise Price	$7.19
Outstanding, Weighted Average Exercise Price, Ending balance	$19.52
Discount [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Granted, Number of Options	370,925
Granted, Weighted Average Exercise Price	$28.14
Granted, Weighted Average Grant-Date Fair Value	$13.88
Market Value [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Granted, Number of Options	21,542
Granted, Weighted Average Exercise Price	$46.03
Granted, Weighted Average Grant-Date Fair Value	$14.18

Stockholders_Equity_and_StockB4

Stockholders' Equity and Stock-Based Compensation Plans - Summarizes the Transactions of the SEUs (Detail) (Stock Equivalent Units [Member], USD $)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Outstanding, Number of Options, Beginning balance	403,262
Exercised, Number of Options	-164,717
Forfeited, Number of Options	-6,442
Outstanding, Number of Options, Ending balance	289,963
Outstanding, Weighted Average Exercise Price, Beginning balance	$3.64
Exercised, Weighted Average Exercise Price	$4.86
Forfeited, Weighted Average Exercise Price	$7.02
Outstanding, Weighted Average Exercise Price, Ending balance	$3.37
Discount [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Granted, Number of Options	50,713
Granted, Weighted Average Exercise Price	$0
Granted, Weighted Average Grant-Date Fair Value	$33.33
Market Value [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Granted, Number of Options	7,147
Granted, Weighted Average Exercise Price	$46.03
Granted, Weighted Average Grant-Date Fair Value	$14.18

Stockholders_Equity_and_StockB5

Stockholders' Equity and Stock-Based Compensation Plans - Fair Value of Liability Cash-Settled Stock Appreciation Rights (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Balance at January 1	$0
Compensation charge for the period	0.1
Balance at September 30	$0.10

Stockholders_Equity_and_StockB6

Stockholders' Equity and Stock-Based Compensation Plans - Assumptions Used in the Monte Carlo Model (Detail) (Monte Carlo Model [Member])	9 Months Ended
	Sep. 30, 2014
Monte Carlo Model [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Dividend yield	1.45%
Volatility of Innospec's share price	28.96%
Risk free interest rate	1.07%

Reclassifications_Out_of_Accum2

Reclassifications Out of Accumulated Other Comprehensive Income/(Loss) - Summary of Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Income tax expense	($4.60)	($4.30)	($12)	($13)
Reclassification Out of Accumulated Other Comprehensive Income/(Loss) [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Total reclassifications	'	'	2.5	'
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	'	'	-1	'
Amortization of actuarial net losses	'	'	4.1	'
Total before tax	'	'	3.1	'
Income tax expense	'	'	-0.6	'
Total reclassifications	'	'	$2.50	'

Reclassifications_Out_of_Accum3

Reclassifications Out of Accumulated Other Comprehensive Income/(Loss) - Changes in Accumulated Other Comprehensive Loss (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Opening balance	'	'	($153.90)	'
Other comprehensive income/(loss) before reclassifications	'	'	-6.2	'
Amounts reclassified from AOCL	'	'	2.5	'
Total other comprehensive income/(loss)	-5.1	3.4	-3.7	1.6
Closing balance	-157.6	'	-157.6	'
Defined Benefit Pension Plan Items [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Opening balance	'	'	-120.2	'
Other comprehensive income/(loss) before reclassifications	'	'	0	'
Amounts reclassified from AOCL	'	'	2.5	'
Total other comprehensive income/(loss)	'	'	2.5	'
Closing balance	-117.7	'	-117.7	'
Cumulative Translation Adjustments [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Opening balance	'	'	-33.7	'
Other comprehensive income/(loss) before reclassifications	'	'	-6.2	'
Amounts reclassified from AOCL	'	'	0	'
Total other comprehensive income/(loss)	'	'	-6.2	'
Closing balance	($39.90)	'	($39.90)	'

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Related Party Transactions [Abstract]	'	'	'
Fees from Smith, Gambrell & Russell	$0.80	$0.90	'
Amount due to Smith, Gambrell & Russell	$0.50	'	$0.20

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (Independence Oilfield Chemicals LLC [Member], USD $)	9 Months Ended	0 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Oct. 27, 2014	Oct. 27, 2014
		Subsequent Event [Member]	Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'
Date of acquisition	27-Oct-14	'	'
Acquired membership interests	'	'	100.00%
Business acquisition, consideration	'	$212.80	'
Business acquisition, initial payment	'	$99	'
Business acquisition, description	'	'Innospec will make two deferred consideration payments, with the first one payable approximately one year after closing, and the second one payable approximately two years after closing, with a portion of such deferred payments payable, at Innospec's election, in shares of Innospec's common stock.	'

Subsequent_Events_Estimated_Al

Subsequent Events - Estimated Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Oct. 27, 2014
In Millions, unless otherwise specified					Subsequent Event [Member]
					Independence Oilfield Chemicals LLC [Member]
Business Acquisition [Line Items]	'	'	'	'	'
Other intangible assets	'	'	'	'	$78.70
Goodwill	187.9	187.9	165.3	149	115.8
Other net assets acquired	'	'	'	'	18.3
Purchase price, net of cash acquired	'	'	'	'	$212.80