Significant Accounting Policies (Policies)	12 Months Ended
Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of DLH Holdings Corp. and its subsidiaries (together with its subsidiaries, "DLH" or the "Company" and also referred to as "we," "us," and "our"), 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 U.S. generally accepted accounting principles ("GAAP") and with the instructions to Form 10-K, Regulation S-X, and Regulation S-K.
New Accounting Pronouncements	New Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which requires companies to record an allowance for expected credit losses over the contractual term of certain financial assets, including short-term trade receivables and contract assets. Additionally, it expands disclosure requirements for credit quality of financial assets. ASU 2016-13 became effective for the Company in the first quarter of fiscal year 2021. The adoption of this standard did not have a material impact on our operating results, financial position, or cash flows. For further detail of our outstanding receivables see Note 7. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848), which provides optional expedients and exceptions for the application of U.S. GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate ("LIBOR") and other references rates expected to be discontinued due to reference rate reform. ASU 2020-04 became effective on March 12, 2020 for all entities meeting certain criteria. The Company may elect to apply the amendments using a prospective approach through December 31, 2022. The Company is currently assessing the impact of electing this standard on its consolidated financial statements and related disclosures and does not expect the impact to be material. In April 2020, the FASB issued a Staff Q&A, Topic 842 and 840: Accounting For Lease Concessions Related to the Effects of the COVID-19 Pandemic in order to provide clarity regarding the accounting treatment for lease concessions provided as a result of COVID-19. Under existing lease guidance, changes to certain lease terms not specified in the original lease agreement require modification accounting treatment. To provide relief, the FASB Staff Q&A permits alternatives to modification accounting under Topic 842. For concessions related to the effects of the COVID-19 pandemic that do not result in a substantial increase in the rights of the lessor or our obligations as the lessee, we are not required to analyze each contract to determine whether enforceable rights and obligations for concessions exist in the lease agreement and can elect to apply or not apply the lease modification guidance in Topic 842. In fiscal year 2021, we elected to account for lease concessions received for one of our operating leases as a resolution of a contingency, whereby we remeasured our lease liability and recorded the adjustment against the right-of-use asset, without reassessing lease classification or modifying the original discount rate. As a result of this election, our lease liability and right-of-use-asset decreased by less than $0.1 million. In August 2020, the FASB issued ASU 2020-06, which amends the measurement and disclosure of convertible instruments, contracts in an entity's own equity, and EPS guidance. The guidance can be adopted using a modified retrospective method or a fully retrospective method. The amendments are effective for fiscal years beginning after December 15, 2021 for public entities, excluding those that are smaller reporting companies. For all other entities the amendments are effective for fiscal years beginning after December 15, 2023. The Company does not expect the update to have a material impact on its consolidated financial statements and related disclosures.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates include valuation of goodwill and intangible assets, interest rate swaps, stock-based compensation, right-of-use assets and liabilities, valuation allowances established against accounts receivable and deferred tax assets, and measurement of loss development on workers' compensation claims. We evaluate these estimates and judgments on an ongoing basis and base our estimates on historical experience, current and expected future outcomes, third-party evaluations, and various other assumptions that we believe are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. We revise material accounting estimates if changes occur, such as more experience is acquired, additional information is obtained, or there is new information on which an estimate was or can be based. Actual results could differ from those estimates. In particular, a material reduction in the fair value of goodwill would have a material adverse effect on the Company’s financial position and results of operations. We account for the effect of a change in accounting estimate during the period in which the change occurs.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of the Company's cash and cash equivalents, accounts receivable, contract assets, accrued expenses, and accounts payable approximate fair value due to the short-term nature of these instruments. The fair values of the Company's debt instruments approximate fair value because the underlying interest rates approximate market rates that the Company could obtain for similar instruments at the balance sheet dates.
Long Lived Assets	Long-lived Assets Our long-lived assets include equipment and improvements, intangible assets, right-of-use assets, and goodwill. The Company continues to review its long-lived assets for possible impairment or loss of value at least annually or more frequently upon the occurrence of an event or when circumstances indicate that a reporting unit’s carrying amount is greater than its fair value. Equipment and improvements are stated at cost. Depreciation and amortization are provided using the straight-line method over the estimated useful asset lives (3 to 7 years) and the shorter of the initial lease term or estimated useful life for leasehold improvements. Intangible assets (other than goodwill) are originally recorded at fair value and are amortized on a straight-line basis over their estimated useful lives of 10 years. Maintenance and repair costs are expensed as incurred. Right-of-use assets are measured at the present value of future minimum lease payments, including all probable renewals, plus lease payments made to the lessor before or at lease commencement and indirect costs paid, less incentives received. Our right-of-use assets include long-term leases for facilities and equipment and are amortized over their respective lease terms.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with the liability method, whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities, using enacted tax rates in effect for the year in which the differences are expected to reverse. Deferred tax assets are reflected on the consolidated balance sheet when it is determined that it is more likely than not that the asset will be realized. This guidance also requires that deferred tax assets be reduced by a valuation allowance if it is more likely than not that some or all of the deferred tax asset will not be realized. We account for uncertain tax positions by recognizing the financial statement effects of a tax position only when, based upon the technical merits, it is "more-likely-than-not" that the position will be sustained upon examination.
Share-based Equity Compensation	Stock-based Equity Compensation The Company uses the fair value-based method for stock-based equity compensation. Options issued are designated as either an incentive stock or a non-statutory stock option. No option may be granted with a term of more than 10 years from the date of grant. Option awards may depend on achievement of certain performance measures determined by the Compensation Committee of our Board. Shares issued upon option exercise are newly issued common shares. All awards to employees and non-employees are recorded at fair value on the date of the grant and expensed over the period of vesting. The Company uses a binomial and Black Scholes option pricing model to estimate the fair value of each stock option at the date of grant. Any consideration paid by the option holders to purchase shares is credited to capital stock.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. We maintain cash balances at financial institutions that are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000. Deposits held with financial institutions may exceed the $250,000 limit.
Earnings per Share	Earnings per ShareBasic earnings per share is calculated by dividing income available to common shareholders by the weighted average number of common stock outstanding and restricted stock grants that vested or are likely to vest during the period. Diluted earnings per share is calculated by dividing income available to common shareholders by the weighted average number of basic common shares outstanding, adjusted to reflect potentially dilutive securities. Diluted earnings per share is calculated using the treasury stock method.
Treasury Stock and Preferred Stock	Treasury Stock The Company periodically purchases its own common stock that is traded on public markets as part of announced stock repurchase programs. The repurchased common stock is classified as treasury stock on the consolidated balance sheets and held at cost. As of September 30, 2021, the Company did not hold any treasury stock. Preferred Stock Our certificate of incorporation authorizes the issuance of "blank check" preferred stock with such designations, rights and preferences as may be determined from time to time by our board of directors up to an aggregate of 5,000,000 shares of preferred stock. As of September 30, 2021, the Company has not issued any preferred stock.
Interest Rate Swap	Interest Rate Swap The Company uses derivative financial instruments to manage interest rate risk associated with its variable debt. The Company's objective in using these interest rate derivatives is to manage its exposure to interest rate movements and reduce volatility of interest expense. The gains and losses due to changes in the fair value of the interest rate swap agreements completely offset changes in the fair value of the hedged portion of the underlying debt. Offsetting changes in fair value of both the interest rate swaps and the hedged portion of the underlying debt are recognized in interest expense in the Consolidated Statements of Operations. The Company does not hold or issue any derivative instrument for trading or speculative purposes.
Revenue Recognition	Revenue Recognition We recognize revenue over time when there is a continuous transfer of control to our customer. For our U.S. government contracts, this continuous transfer of control to the customer is supported by clauses in the contract that allow the U.S. government to unilaterally terminate the contract for convenience, pay us for costs incurred plus a reasonable profit and take control of any work in process. When control is transferred over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. For services contracts, we satisfy our performance obligations as services are rendered. We use cost-based input and time-based output methods to measure progress. Contract costs include labor, material and allocable indirect expenses. For time-and-material contracts, we bill the customer per labor hour and per material, and revenue is recognized in the amount invoiced since the amount corresponds directly to the value of our performance to date. We consider control to transfer when we have a present right to payment. Essentially, all of our contracts satisfy their performance obligations over time. Contracts are often modified to account for changes in contract specifications and requirements. Contract modifications impact performance obligations when the modification either creates new or changes the existing enforceable rights and obligations. The effect of a contract modification on the transaction price and our measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue and profit cumulatively. Furthermore, a significant change in one or more estimates could affect the profitability of our contracts. We recognize adjustments in estimated profit on contracts in the period identified. For time-and-materials contracts, revenue is recognized to the extent of billable rates times hours delivered plus materials and other reimbursable costs incurred. Revenue for cost-reimbursable contracts is recorded as reimbursable costs are incurred, including an estimated share of the applicable contractual fees earned. For firm-fixed-price contracts, the consideration received for our performance is set at a predetermined price. Revenue for our firm-fixed-price contracts is recognized over time using a straight-line measure of progress or using the percentage-of-completion method whereby progress toward completion is based on a comparison of actual costs incurred to total estimated costs to be incurred over the contract term. Contract costs are expensed as incurred. Estimated losses are recognized when identified. Contract assets - Amounts are invoiced as work progresses in accordance with agreed-upon contractual terms. In part, revenue recognition occurs before we have the right to bill, resulting in contract assets. These contract assets are reported within receivables, net on our consolidated balance sheets and are invoiced in accordance with payment terms defined in each contract. Period end balances will vary from period to period due to agreed-upon contractual terms. Contract liabilities - Amounts are a result of billings in excess of costs incurred. Disaggregation of revenue from contracts with customers We disaggregate our revenue from contracts with customers by customer, contract type, as well as whether the Company acts as prime contractor or subcontractor. We believe these categories best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors.

Significant Accounting Policies (Policies)

12 Months Ended

Sep. 30, 2021

Basis of Presentation The accompanying consolidated financial statements include the accounts of DLH Holdings Corp. and its subsidiaries (together with its subsidiaries, "DLH" or the "Company" and also referred to as "we," "us," and "our"), 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 U.S. generally accepted accounting principles ("GAAP") and with the instructions to Form 10-K, Regulation S-X, and Regulation S-K.

New Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which requires companies to record an allowance for expected credit losses over the contractual term of certain financial assets, including short-term trade receivables and contract assets. Additionally, it expands disclosure requirements for credit quality of financial assets. ASU 2016-13 became effective for the Company in the first quarter of fiscal year 2021. The adoption of this standard did not have a material impact on our operating results, financial position, or cash flows. For further detail of our outstanding receivables see Note 7.

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848), which provides optional expedients and exceptions for the application of U.S. GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate ("LIBOR") and other references rates expected to be discontinued due to reference rate reform. ASU 2020-04 became effective on March 12, 2020 for all entities meeting certain criteria. The Company may elect to apply the amendments using a prospective approach through December 31, 2022. The Company is currently assessing the impact of

electing this standard on its consolidated financial statements and related disclosures and does not expect the impact to be material.

In April 2020, the FASB issued a Staff Q&A, Topic 842 and 840: Accounting For Lease Concessions Related to the Effects of the COVID-19 Pandemic in order to provide clarity regarding the accounting treatment for lease concessions provided as a result of COVID-19. Under existing lease guidance, changes to certain lease terms not specified in the original lease agreement require modification accounting treatment. To provide relief, the FASB Staff Q&A permits alternatives to modification accounting under Topic 842. For concessions related to the effects of the COVID-19 pandemic that do not result in a substantial increase in the rights of the lessor or our obligations as the lessee, we are not required to analyze each contract to determine whether enforceable rights and obligations for concessions exist in the lease agreement and can elect to apply or not apply the lease modification guidance in Topic 842. In fiscal year 2021, we elected to account for lease concessions received for one of our operating leases as a resolution of a contingency, whereby we remeasured our lease liability and recorded the adjustment against the right-of-use asset, without reassessing lease classification or modifying the original discount rate. As a result of this election, our lease liability and right-of-use-asset decreased by less than $0.1 million.

In August 2020, the FASB issued ASU 2020-06, which amends the measurement and disclosure of convertible instruments, contracts in an entity's own equity, and EPS guidance. The guidance can be adopted using a modified retrospective method or a fully retrospective method. The amendments are effective for fiscal years beginning after December 15, 2021 for public entities, excluding those that are smaller reporting companies. For all other entities the amendments are effective for fiscal years beginning after December 15, 2023. The Company does not expect the update to have a material impact on its consolidated financial statements and related disclosures.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates include valuation of goodwill and intangible assets, interest rate swaps, stock-based compensation, right-of-use assets and liabilities, valuation allowances established against accounts receivable and deferred tax assets, and measurement of loss development on workers' compensation claims. We evaluate these estimates and judgments on an ongoing basis and base our estimates on historical experience, current and expected future outcomes, third-party evaluations, and various other assumptions that we believe are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. We revise material accounting estimates if changes occur, such as more experience is acquired, additional information is obtained, or there is new information on which an estimate was or can be based. Actual results could differ from those estimates. In particular, a material reduction in the fair value of goodwill would have a material adverse effect on the Company’s financial position and results of operations. We account for the effect of a change in accounting estimate during the period in which the change occurs.

Fair Value of Financial Instruments

The carrying amounts of the Company's cash and cash equivalents, accounts receivable, contract assets, accrued expenses, and accounts payable approximate fair value due to the short-term nature of these instruments. The fair values of the Company's debt instruments approximate fair value because the underlying interest rates approximate market rates that the Company could obtain for similar instruments at the balance sheet dates.

Long Lived Assets

Long-lived Assets

Our long-lived assets include equipment and improvements, intangible assets, right-of-use assets, and goodwill. The Company continues to review its long-lived assets for possible impairment or loss of value at least annually or more frequently upon the occurrence of an event or when circumstances indicate that a reporting unit’s carrying amount is greater than its fair value.

Equipment and improvements are stated at cost. Depreciation and amortization are provided using the straight-line method over the estimated useful asset lives (3 to 7 years) and the shorter of the initial lease term or estimated useful life for leasehold improvements. Intangible assets (other than goodwill) are originally recorded at fair value and are amortized on a straight-line basis over their estimated useful lives of 10 years. Maintenance and repair costs are expensed as incurred.

Right-of-use assets are measured at the present value of future minimum lease payments, including all probable renewals, plus lease payments made to the lessor before or at lease commencement and indirect costs paid, less incentives received. Our right-of-use assets include long-term leases for facilities and equipment and are amortized over their respective lease terms.

Income Taxes

The Company accounts for income taxes in accordance with the liability method, whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities, using enacted tax rates in effect for the year in which the differences are expected to reverse. Deferred tax assets are reflected on the consolidated balance sheet when it is determined that it is more likely than not that the asset will be realized. This guidance also requires that

deferred tax assets be reduced by a valuation allowance if it is more likely than not that some or all of the deferred tax asset will not be realized. We account for uncertain tax positions by recognizing the financial statement effects of a tax position only when, based upon the technical merits, it is "more-likely-than-not" that the position will be sustained upon examination.

Share-based Equity Compensation

Stock-based Equity Compensation

The Company uses the fair value-based method for stock-based equity compensation. Options issued are designated as either an incentive stock or a non-statutory stock option. No option may be granted with a term of more than 10 years from the date of grant. Option awards may depend on achievement of certain performance measures determined by the Compensation Committee of our Board. Shares issued upon option exercise are newly issued common shares. All awards to employees and non-employees are recorded at fair value on the date of the grant and expensed over the period of vesting. The Company uses a binomial and Black Scholes option pricing model to estimate the fair value of each stock option at the date of grant. Any consideration paid by the option holders to purchase shares is credited to capital stock.

Cash and Cash Equivalents

We consider all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. We maintain cash balances at financial institutions that are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000. Deposits held with financial institutions may exceed the $250,000 limit.

Earnings per Share

Earnings per ShareBasic earnings per share is calculated by dividing income available to common shareholders by the weighted average number of common stock outstanding and restricted stock grants that vested or are likely to vest during the period. Diluted earnings per share is calculated by dividing income available to common shareholders by the weighted average number of basic common shares outstanding, adjusted to reflect potentially dilutive securities. Diluted earnings per share is calculated using the treasury stock method.

Treasury Stock and Preferred Stock

Treasury Stock

The Company periodically purchases its own common stock that is traded on public markets as part of announced stock repurchase programs. The repurchased common stock is classified as treasury stock on the consolidated balance sheets and held

at cost. As of September 30, 2021, the Company did not hold any treasury stock.

Preferred Stock

Our certificate of incorporation authorizes the issuance of "blank check" preferred stock with such designations, rights and preferences as may be determined from time to time by our board of directors up to an aggregate of 5,000,000 shares of preferred stock. As of September 30, 2021, the Company has not issued any preferred stock.

Interest Rate Swap

The Company uses derivative financial instruments to manage interest rate risk associated with its variable debt. The Company's objective in using these interest rate derivatives is to manage its exposure to interest rate movements and reduce volatility of interest expense. The gains and losses due to changes in the fair value of the interest rate swap agreements completely offset changes in the fair value of the hedged portion of the underlying debt. Offsetting changes in fair value of both the interest rate swaps and the hedged portion of the underlying debt are recognized in interest expense in the Consolidated Statements of Operations. The Company does not hold or issue any derivative instrument for trading or speculative purposes.

Revenue Recognition

We recognize revenue over time when there is a continuous transfer of control to our customer. For our U.S. government contracts, this continuous transfer of control to the customer is supported by clauses in the contract that allow the U.S. government to unilaterally terminate the contract for convenience, pay us for costs incurred plus a reasonable profit and take control of any work in process. When control is transferred over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. For services contracts, we satisfy our performance obligations as services are rendered. We use cost-based input and time-based output methods to measure progress.

Contract costs include labor, material and allocable indirect expenses. For time-and-material contracts, we bill the customer per labor hour and per material, and revenue is recognized in the amount invoiced since the amount corresponds directly to the value of our performance to date. We consider control to transfer when we have a present right to payment. Essentially, all of our contracts satisfy their performance obligations over time. Contracts are often modified to account for changes in contract specifications and requirements. Contract modifications impact performance obligations when the modification either creates new or changes the existing enforceable rights and obligations. The effect of a contract modification on the transaction price and our measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue and profit cumulatively. Furthermore, a significant change in one or more estimates could affect the profitability of our contracts. We recognize adjustments in estimated profit on contracts in the period identified.

For time-and-materials contracts, revenue is recognized to the extent of billable rates times hours delivered plus materials and other reimbursable costs incurred. Revenue for cost-reimbursable contracts is recorded as reimbursable costs are incurred, including an estimated share of the applicable contractual fees earned. For firm-fixed-price contracts, the consideration received for our performance is set at a predetermined price. Revenue for our firm-fixed-price contracts is recognized over time using a straight-line measure of progress or using the percentage-of-completion method whereby progress toward completion is based on a comparison of actual costs incurred to total estimated costs to be incurred over the contract term. Contract costs are expensed as incurred. Estimated losses are recognized when identified.

Contract assets - Amounts are invoiced as work progresses in accordance with agreed-upon contractual terms. In part, revenue recognition occurs before we have the right to bill, resulting in contract assets. These contract assets are reported within receivables, net on our consolidated balance sheets and are invoiced in accordance with payment terms defined in each contract. Period end balances will vary from period to period due to agreed-upon contractual terms.

Contract liabilities - Amounts are a result of billings in excess of costs incurred.

Disaggregation of revenue from contracts with customers We disaggregate our revenue from contracts with customers by customer, contract type, as well as whether the Company acts as prime contractor or subcontractor. We believe these categories best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors.