DEBT (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended
Jun. 30, 2014
Other
Letter of credit issued for worker's compensation insurance carrier as part of the entity's self-insured loss control program	$ 0.4
Revolving Credit Facility [Member]
Revolving credit facility
Revolving credit limit	70.0
Increase in borrowing capacity available under loan accordion	25.0
Additional credit advances for certain inventory purchases	$ 10.0
Automatic renewal period of agreement unless terminated	1 year
Basis points added to reference rate (as a percent)	0.25%
Period considered for computing fixed charge coverage ratio	12 months
Threshold of excess availability of credit as a percentage of maximum loan limit, required for financial covenant compliance	10.00%
Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Revolving credit facility
Variable rate basis	LIBOR
Revolving Credit Facility [Member] \| Prime Rate [Member]
Revolving credit facility
Variable rate basis	Prime rate
Revolving Credit Facility [Member] \| Minimum [Member]
Revolving credit facility
Notice period prior to the end of any original or renewal term of the agreement required for terminating the agreement either by the borrower or lender	90 days
Fixed charge coverage ratio	1.0
Fixed charge coverage ratio required to be maintained immediately after giving effect to any such dividend or distribution payments	1.10
Revolving Credit Facility [Member] \| Minimum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Revolving credit facility
Basis points added to reference rate (as a percent)	1.25%
Revolving Credit Facility [Member] \| Maximum [Member]
Revolving credit facility
Restricted amount of dividends on common stock (in dollars per share)	$ 1.00
Revolving Credit Facility [Member] \| Maximum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Revolving credit facility
Basis points added to reference rate (as a percent)	1.75%

Represents the automatic renewal period of line of credit facility unless terminated by either the borrower or lender.

No definition available.

Name:	dit_LineOfCreditFacilityAutomaticRenewalPeriodOfAgreement
Namespace Prefix:	dit_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents fixed charge coverage ratio required to be maintained immediately after giving effect to any such dividend or distribution payments.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityDividendCovenantFixedChargeCoverageRatio
Namespace Prefix:	dit_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the restricted amount of dividends on common stock.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityDividendsRestrictionOnCommonStock
Namespace Prefix:	dit_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the threshold of excess availability of credit expressed as a percentage of maximum loan limit, as it relates to requiring a fixed charge ratio.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityFinancialCovenantExcessCapacityThresholdPercentageOfMaximumLoanLimit
Namespace Prefix:	dit_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents fixed charge coverage ratio required to be maintained during any previous twelve month period if excess capacity falls below a defined threshold per the terms of the credit agreement.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityFinancialCovenantFixedChargeCoverageRatio
Namespace Prefix:	dit_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period considered for computing fixed charge coverage ratio.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityFinancialCovenantPeriodConsideredForComputingFixedChargeCoverageRatio
Namespace Prefix:	dit_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase in borrowing capacity available under the credit facility attributable to the accordion feature.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityIncreaseAvailableAccordionFeature
Namespace Prefix:	dit_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the period of time prior to the end of the original term of the agreement or the end of any renewal period in which either the borrower or lender may terminate the line of credit facility.

+ References

No definition available.

+ Details

Name:	dit_LineOfCreditFacilityNoticePeriodForTerminatingAgreement
Namespace Prefix:	dit_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for financing purchases of goods acquired for inventory or imminent delivery to a customer.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
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

Reference 1: 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

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

+ Details

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

- Details

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