| **Basis of Presentation**                                                           | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
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| **Organization, Consolidation and Presentation of Financial Statements [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Basis of Presentation                                                               | Basis of Presentation The accompanying unaudited consolidated financial statements include the accounts of DLH and its subsidiaries, all of which are wholly owned. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X.  Accordingly, these statements do not include all of the information and footnotes required by generally accepted accounting principles ("GAAP") for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the quarter ended June 30, 2016 are not necessarily indicative of the results that may be expected for the year ending September 30, 2016. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company's Annual report on Form 10-K for the year ended September 30, 2015 filed with the Securities and Exchange Commission on December 16, 2015. |

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| - Definition
The entire disclosure for the business description and basis of presentation concepts.  Business description describes the nature and type of organization including but not limited to organizational structure as may be applicable to holding companies, parent and subsidiary relationships, business divisions, business units, business segments, affiliates and information about significant ownership of the reporting entity.  Basis of presentation describes the underlying basis used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).
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| - References
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