Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2016
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements include the accounts of Star Gas Partners and its subsidiaries. All material inter-company items and transactions have been eliminated in consolidation. The financial information included herein is unaudited; however, such information reflects all adjustments (consisting solely of normal recurring adjustments), which are, in the opinion of management, necessary for the fair statement of financial condition and results for the interim periods. Due to the seasonal nature of the Partnership’s business, the results of operations and cash flows for the six month period ended March 31, 2016, and March 31, 2015, are not necessarily indicative of the results to be expected for the full year. These interim financial statements of the Partnership have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information and Rule 10-01 of Regulation S-X of the U.S. Securities and Exchange Commission and should be read in conjunction with the financial statements included in the Partnership’s Annual Report on Form 10-K for the year ended September 30, 2015.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net income (loss) and other comprehensive income (loss). Other comprehensive income (loss) consists of the unrealized gain (loss) amortization on the Partnership’s pension plan obligation for its two frozen defined benefit pension plans and the corresponding tax effect.
Weather Hedge Contract	Weather Hedge Contract To partially mitigate the adverse effect of warm weather on cash flows, the Partnership has used weather hedge contracts for a number of years. Weather hedge contracts are recorded in accordance with the intrinsic value method defined by the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 815-45-15 Derivatives and Hedging, Weather Derivatives. The premium paid is included in the caption Prepaid Expenses and Other Current Assets in the accompanying balance sheets and amortized over the life of the contract, with the intrinsic value method applied at each interim period. For fiscal years 2016 and 2017 the Partnership has a weather hedge contract with Swiss Re under which the Partnership is entitled to receive a payment of $35,000 per heating degree-day shortfall, when the accumulated number of heating degree-days in the entire hedge period is less than approximately 92.5% of the ten year average, the Payment Threshold as defined in the contract. The hedge covers the five month period from November 1, through March 31, taken as a whole, and has a maximum payout of $12.5 million for each respective fiscal year. The amount due to the Partnership at March 31, 2016 is $12.5 million based on the degree-day shortfall experienced during the most recent five month hedge period. In April 2016, the Partnership received $12.5 million from Swiss Re.
New England Teamsters and Trucking Industry Pension Fund ("the NETTI Fund") Liability	New England Teamsters and Trucking Industry Pension Fund (“the NETTI Fund”) Liability As of March 31, 2016 we had $0.1 million and $17.6 million included in the captions Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities, respectively, on our condensed consolidated balance sheet representing the remaining balance of the NETTI withdrawal liability. Based on the borrowing rates currently available to the Partnership for long-term financing of a similar maturity, the fair value of the NETTI withdrawal liability as of March 31, 2016 was $17.1 million. We utilized Level 2 inputs in the fair value hierarchy of valuation techniques to determine the fair value of this liability.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This ASU will replace the latest revenue recognition guidance in GAAP when it becomes effective. This new guidance is effective for our annual reporting period beginning in the first quarter of fiscal 2019, with early adoption permitted beginning in the first quarter of fiscal 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Partnership is evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Partnership has not yet selected a transition method nor has it determined the timing of adoption. In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The update requires debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability instead of being presented as an asset. The update requires retrospective application and represents a change in accounting principle. The update is effective for our annual reporting period beginning in the first quarter of fiscal 2017, with early adoption permitted. The impact of ASU No. 2015-03 will be limited to the presentation of debt issuance cost on our balance sheet. In July 2015, the FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory. The update changes the measurement principle for inventory from the lower of cost or market to the lower of cost and net realizable value. This new guidance is effective for our annual reporting period beginning in the first quarter of fiscal 2018, with early adoption permitted. The Partnership does not expect ASU No. 2015-11 to have a material impact on its consolidated financial statements and related disclosures. In September 2015, the FASB issued ASU No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments, which requires an acquiring entity to recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The acquiring entity is required to record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. In addition, the acquiring entity is to present separately on the face of its income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods as if the adjustment to the provisional amounts had been recognized as of the acquisition date. This new guidance is effective for our annual reporting period beginning in the first quarter of fiscal 2017. The Partnership does not expect ASU No. 2015-16 to have a material impact on its consolidated financial statements and related disclosures. In November 2015, FASB issued ASU No. 2015-17, Income Taxes - Balance Sheet Classification of Deferred Taxes, which eliminates the requirement for companies to present deferred tax assets and liabilities as current and non-current in a classified balance sheet. Instead, companies will be required to classify all deferred tax assets and liabilities as non-current. This new guidance is effective for our annual reporting period beginning in the first quarter of fiscal 2018, with early adoption permitted. The standard permits the use of either the prospective or retrospective transition method. The Partnership is evaluating the effect that ASU No. 2015-17 will have on its consolidated financial statements and related disclosures. The Partnership has not yet selected a transition method nor has it determined the timing of adoption. In February 2016, the FASB issued ASU No. 2016-02, Leases. The update requires all leases with a term greater than twelve months to be recognized on the balance sheet through a right-of-use asset and a lease liability, and the disclosure of key information pertaining to leasing arrangements. This new guidance is effective for our annual reporting period beginning in the first quarter of fiscal 2020, with early adoption permitted. The Partnership is evaluating the effect that ASU No. 2016-02 will have on its consolidated financial statements and related disclosures. The Partnership has not yet selected a transition method nor has it determined the timing of adoption.

Disclosure of accounting policy for pension and other postretirement benefit plans. This accounting policy may address (1) the types of plans sponsored by the entity, and the benefits provided by each plan (2) groups that participate in (or are covered by) each plan (3) how plan assets, liabilities and expenses are measured, including the use of any actuaries and (4) significant assumptions used by the entity to value plan assets and liabilities and how such assumptions are derived.