XML 70 R51.htm IDEA: XBRL DOCUMENT v2.4.1.9

Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
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 2011 onwards. The Company's subsidiaries in foreign tax jurisdictions are open to examination including France (2013 onwards), Germany (2010 onwards), Switzerland (2013 onwards) and the United Kingdom (2013 onwards).
Unremitted earnings		$ 743iosp_UnremittedEarningOfForeignSubsidiary
France [Member]
Income Tax Contingency [Line Items]
Open tax year	2013
Germany [Member]
Income Tax Contingency [Line Items]
Open tax year	2010
Switzerland [Member]
Income Tax Contingency [Line Items]
Open tax year	2013
United Kingdom [Member]
Income Tax Contingency [Line Items]
Open tax year	2013

X

- Definition

Unremitted earning of foreign subsidiary.

+ References

No definition available.

+ Details

Name:	iosp_UnremittedEarningOfForeignSubsidiary
Namespace Prefix:	iosp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_IncomeTaxContingencyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (d)(2)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

+ Details

Name:	us-gaap_IncomeTaxExaminationDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tax year that remains open to examination under enacted tax laws, in CCYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

+ Details

Name:	us-gaap_OpenTaxYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_CH
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_DE
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_FR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_GB
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: