| **Basis of Presentation**                                                           | 12 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 and with the instructions to Form 10-K, Regulation S-X, and Regulation S-K. |

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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
No definition available.
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