| **Employee Benefit Plans**                            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| **Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Employee Benefits Plans                               | Employee Benefit PlansAs of September 30, 2016, DLH and its subsidiaries maintain the DLH 401(k) Plan (the "401(k) Plan") , a defined contribution and supplemental pension plan for the benefit of its eligible employees. DLH may provide a discretionary matching contribution of of a participant's elective contributions under the 401 (k) Plan. DLH recorded related expense of $142.0 thousand in fiscal 2016 and $24.0 thousand in fiscal year 2015. A participant is always fully vested in his or her elective contributions and vests in Company matching contributions over a 4 year period. |

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| - References
No definition available.
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| - Definition
The entire disclosure for pension and other postretirement benefits.
+ References
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