XML 30 R47.htm IDEA: XBRL DOCUMENT v2.4.0.8

Goodwill - Summary of Goodwill (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Historical accumulated amortization	$ 298.5	$ 298.5

X

- Definition

Goodwill historical accumulated amortization.

+ References

No definition available.

+ Details

Name:	iosp_GoodwillHistoricalAccumulatedAmortization
Namespace Prefix:	iosp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

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