XML 95 R84.htm IDEA: XBRL DOCUMENT v2.4.1.9

Income Taxes - Details of Deferred Tax Asset Valuation Allowance (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
At January 1	$ 0us-gaap_DeferredTaxAssetsValuationAllowance	$ 0us-gaap_DeferredTaxAssetsValuationAllowance	$ (7.5)us-gaap_DeferredTaxAssetsValuationAllowance
Change in foreign tax credits	0iosp_ForeignTaxCreditChangeDuringPeriod	0iosp_ForeignTaxCreditChangeDuringPeriod	7.5iosp_ForeignTaxCreditChangeDuringPeriod
At December 31	$ 0us-gaap_DeferredTaxAssetsValuationAllowance	$ 0us-gaap_DeferredTaxAssetsValuationAllowance	$ 0us-gaap_DeferredTaxAssetsValuationAllowance

X

- Definition

Foreign Tax Credit Change During Period

+ References

No definition available.

+ Details

Name:	iosp_ForeignTaxCreditChangeDuringPeriod
Namespace Prefix:	iosp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

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