Debt Description (Details) In Thousands, unless otherwise specified	12 Months Ended
Sep. 30, 2011 Bank Of America And Wells Fargo Facilities [Member] Second Amendment [Member] USD ($)	Sep. 30, 2011 Fortis Facility [Member]	Sep. 30, 2010 Fortis Facility [Member] GBP (£)	Sep. 30, 2011 Wells Fargo Facility [Member] GBP (£)
Maximum Borrowing Capacity	$ 100,000		£ 12,000	£ 12,500
Initiation Date	August 10, 2010		September 30, 2010	November 5, 2010
Termination Date	March 1, 2013	November 5, 2010
Covenant Terms				maintain a minimum tangible net worth of £3,000
Interest Rate at Period End	1.61%			1.63%
Interest Rate Description	The variable interest rate is equal to the Daily LIBOR Floating Rate or the LIBOR 1-month fixed rate (at MWI Co.’s option) plus a margin ranging from 1.50% to 2.25%.		variable interest rate equal to a base rate of 0.50% plus GBP one-month LIBOR plus a margin of 0.85%.	Interest is based on LIBOR for the applicable interest period plus an applicable margin of 1.05% to 1.90%.
Commitment Fee Description	The commitment fee ranged from 0.2% to 0.35% depending on the funded debt to EBITDA ratio.

Description of the fees for amounts available, but unused under the credit facility.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeeDescription
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the conditions for borrowing under the credit facility including the nature of any restrictions.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCovenantTerms
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects when the credit facility first became available, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDescription
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant