| **DEBT: (Details) (USD $)**                                                      | 0 Months Ended | 3 Months Ended |        | 0 Months Ended | 1 Months Ended |             |             |               | 3 Months Ended                 |        |           |        |             |           |           | 3 Months Ended                 |                |        |
|----------------------------------------------------------------------------------|----------------|----------------|--------|----------------|----------------|-------------|-------------|---------------|--------------------------------|--------|-----------|--------|-------------|-----------|-----------|--------------------------------|----------------|--------|
||
| **DEBT**                                                                         |           |           |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Term of debt instrument (years)                                                  |           |           |   | 2 years        |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Maximum availability                                                             |           |           |   | $ 1,500,000.0  | $ 6,000,000    | $ 3,000,000 | $ 3,000,000 | $ 2,500,000.0 |                           |   | $ 750,000 |   | $ 1,000,000 | $ 500,000 | $ 500,000 |                           | $ 1,030,000.00 |   |
| Extended term of debt instrument (months)                                        | 12 months      |           |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Adjusted sublimit                                                                |           |           |   |           | 4,000,000      |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Repayment of over-advance accommodation                                          |           |           |   |           | 500,000        |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Accounts advance rate (percent)                                                  |           |           |   |           |           | 85.00%      |        |          |                           | 75.00% |      |   |        |      |      |                           |           |   |
| Interest rate premium (percent)                                                  |           |           |   |           |           |        |        |          |                           | 2.00%  |      |   |        |      |      |                           |           |   |
| Interest rate (percent)                                                          |           |           |   |           |           | 3.25%       |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Margin (percent)                                                                 |           |           |   |           |           |        |        |          | 1.95%                          |   |      |   |        |      |      | 3.95%                          |           |   |
| Reference rate, description                                                      |           |           |   |           |           |        |        |          | Wall Street Journal Prime rate |   |      |   |        |      |      | Wall Street Journal Prime rate |           |   |
| Monthly service charge based on the average daily loan balance (percent)         |           | 0.65%          |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Interest rate (percent)                                                          |           | 5.20%          | 7.20%  |           |           |        |        |          |                           |   |      | 7.20%  |        |      |      |                           |           | 5.20%  |
| Amount of unused availability under the line                                     |           |           |   |           |           | 1,100,000   |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Amount outstanding                                                               |           |           |   |           |           | 900,000     |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Maximum amount of equity interest that the entity can redeem, retire or purchase |           | $ 50,000       |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Notice period to terminate the Loan Agreement                                    |           | 60 days        |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |
| Origination fee (percent)                                                        |           | 1.00%          |   |           |           |        |        |          |                           |   |      |   |        |      |      |                           |           |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the maximum amount of equity that can be redeemed, retired or repurchased by the entity as per the customary covenants of the loan agreement.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentCovenantRestrictionsOnMaximumRedemptionRetirementRepurchaseOfEquity**Namespace Prefix:**dlhc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the period from the maturity date of the debt for which the debt instrument can be extended.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentExtensionPeriod**Namespace Prefix:**dlhc_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the interest rate premium payable for certain funds borrowed under the loan agreement.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentInterestRatePremium**Namespace Prefix:**dlhc_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the percentage of monthly service charge payable, as per the loan agreement, that is calculated on the basis of average daily loan balance.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentMonthlyServiceChargePercentageBasedOnAverageDailyLoanBalance**Namespace Prefix:**dlhc_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the term of the debt instrument under an agreement.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentTerm**Namespace Prefix:**dlhc_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the notice period that the lender must provide to the entity to terminate the loan agreement.
+ References
No definition available.
+ Details**Name:**dlhc_DebtInstrumentTerminationNoticePeriod**Namespace Prefix:**dlhc_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the adjusted sublimit amount under the credit facility.
+ References
No definition available.
+ Details**Name:**dlhc_LineOfCreditFacilityAdjustedSublimitAmount**Namespace Prefix:**dlhc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the rate at which loans are advanced as per the loan agreement.
+ References
No definition available.
+ Details**Name:**dlhc_LineOfCreditFacilityLoanAdvanceRate**Namespace Prefix:**dlhc_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the percentage of origination fee under the line of credit facility.
+ References
No definition available.
+ Details**Name:**dlhc_LineOfCreditFacilityLoanOriginationFeePercentage**Namespace Prefix:**dlhc_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the repayment of over advance accommodation to lender.
+ References
No definition available.
+ Details**Name:**dlhc_RepaymentOfAdvanceAccommodation**Namespace Prefix:**dlhc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The percentage points added to the reference rate to compute the variable rate on the debt instrument.
+ References
No definition available.
+ Details**Name:**us-gaap_DebtInstrumentBasisSpreadOnVariableRate**Namespace Prefix:**us-gaap_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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 |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effective interest rate at the end of the reporting period.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_DebtInstrumentInterestRateAtPeriodEnd**Namespace Prefix:**us-gaap_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Interest rate stated in the contractual debt agreement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_DebtInstrumentInterestRateStatedPercentage**Namespace Prefix:**us-gaap_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount borrowed under the credit facility as of the balance sheet date.
+ 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
+ Details**Name:**us-gaap_LineOfCreditFacilityAmountOutstanding**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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 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 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=d3e13212-122682Reference 3: 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 |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).
+ 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=d3e13212-122682Reference 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_LineOfCreditFacilityRemainingBorrowingCapacity**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |