Assets and Liabilities Measured at Fair Value (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-cash impairment charge of related to trade name intangibles	$ 60.7
Accumulated goodwill impairment losses	200.5	200.5
Water & Fluid Solutions \| Residential Filtration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accumulated goodwill impairment losses		$ 200.5

Impairment recognized during the period and allocated to the reportable segment that results from the write-down of indefinite-lived intangible assets after comparing the implied fair value of reporting unit indefinite-lived intangible assets with the carrying amount of that indefinite-lived intangible assets, which are assessed at least annually for impairment.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 3

-Subparagraph (b),(d)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16373-109275

Name:	us-gaap_IndefiniteLivedIntangibleAssetsImpairmentLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration