Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation (Policies)	Jun. 30, 2016
Accounting Policies [Abstract]
Fair Value of Financial Instruments	The carrying amounts of our financial instruments reported on the balance sheet as of June 30, 2016, approximated fair value due either to length to maturity or existence of variable interest rates, which approximate prevailing market rates.
Use of Estimates	The preparation of unaudited condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates made by us in the accompanying unaudited condensed consolidated financial statements include valuation allowances, valuation of goodwill and intangible assets, valuation of long-lived assets, and valuation of accruals. Actual results could differ from those estimates.
Consolidation	In order to provide comparability between periods presented, certain amounts have been reclassified from the previously reported consolidated financial statements to conform to the unaudited condensed consolidated financial statement presentation for the current period. The unaudited condensed consolidated financial statements include our accounts and the accounts of our subsidiaries, all of which are wholly owned. All significant intercompany transactions and accounts have been eliminated.
New Accounting Pronouncements	In May 2014, the FASB issued Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (ASU 2014-9), a converged standard on revenue recognition. The new pronouncement requires revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also specifies the accounting for some costs to obtain or fulfill a contract with a customer, as well as enhanced disclosure requirements. ASU 2014-9 is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Early adoption is permitted for annual reporting periods beginning after December 15, 2016. We currently do not believe the adoption of this standard will have a material impact on our consolidated financial statements. In July 2015, the FASB issued ASU No. 2015-11, “Inventory (Topic 330).” The pronouncement was issued to simplify the measurement of inventory and changes the measurement from lower of cost or market to lower of cost and net realizable value. This pronouncement is effective for reporting periods beginning after December 15, 2016. The adoption of ASU 2015-11 is not expected to have a significant impact on the Company’s consolidated financial position or results of operations. In November 2015, FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes, which eliminates the current requirement to present deferred tax liabilities and assets as current and noncurrent in a classified balance sheet. Instead, entities will be required to classify all deferred tax assets and liabilities as noncurrent. This ASU is effective for annual periods beginning after fiscal December 15, 2017 and early adoption is permitted as of the beginning of an interim or annual reporting period. We retrospectively adopted ASU 2015-17 as of June 30, 2016, and as a result have reported deferred tax assets and liabilities as noncurrent on the balance sheet for all periods presented. This early adoption resulted in approximately $9.3 million in deferred tax assets previously reported as current assets in the consolidated balance sheet as of September 30, 2015 being recorded as noncurrent assets as of September 30, 2015. Because the application of this guidance affects classification only, such reclassifications did not have a material effect on the Company’s consolidated financial position or results of operations. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This update requires organizations to recognize lease assets and lease liabilities on the balance sheet and also disclose key information about leasing arrangements. This ASU is effective for annual reporting periods beginning on or after December 15, 2018, and interim periods within those annual periods. Earlier application is permitted for all entities as of the beginning of an interim or annual period. We are currently evaluating the impact the adoption of this ASU will have on our consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, “Compensation – Stock Compensation (Topic 718).” This update was issued as part of the FASB’s simplification initiative and affects all entities that issue share-based payment awards to their employees. The amendments in this update cover such areas as the recognition of excess tax benefits and deficiencies, the classification of those excess tax benefits on the statement of cash flows, an accounting policy election for forfeitures, the amount an employer can withhold to cover income taxes and still qualify for equity classification and the classification of those taxes paid on the statement of cash flows. This update is effective for annual and interim periods beginning after December 15, 2016, which will require us to adopt these provisions in the first quarter of fiscal 2018. This guidance will be applied either prospectively, retrospectively or using a modified retrospective transition method, depending on the area covered in this update. Early adoption is permitted. We have not yet selected a transition date nor have we determined the effect of the standard on our ongoing financial reporting.
Revenue Recognition	We recognize revenue from boat, motor, and trailer sales, and parts and service operations at the time the boat, motor, trailer, or part is delivered to or accepted by the customer or the service is completed. We recognize deferred revenue from service operations and slip and storage services on a straight-line basis over the term of the contract or when service is completed. We recognize commissions earned from a brokerage sale at the time the related brokerage transaction closes. We recognize commissions earned by us for placing notes with financial institutions in connection with customer boat financing when we recognize the related boat sales. We recognize marketing fees earned on credit, life, accident, disability, gap, and hull insurance products sold by third-party insurance companies at the later of customer acceptance of the insurance product as evidenced by contract execution or when the related boat sale is recognized. Pursuant to negotiated agreements with financial and insurance institutions, we are charged back for a portion of these fees should the customer terminate or default on the related finance or insurance contract before it is outstanding for a stipulated minimum period of time. We base the chargeback allowance, which was not material to the unaudited condensed consolidated financial statements taken as a whole as of June 30, 2016, on our experience with repayments or defaults on the related finance or insurance contracts. We also recognize commissions earned on extended warranty service contracts sold on behalf of third-party insurance companies at the later of customer acceptance of the service contract terms as evidenced by contract execution or recognition of the related boat sale. We are charged back for a portion of these commissions should the customer terminate or default on the service contract prior to its scheduled maturity. We determined the chargeback allowance, which was not material to the unaudited condensed consolidated financial statements taken as a whole as of June 30, 2016, based upon our experience with terminations or defaults on the service contracts.
Inventories	Inventory costs consist of the amount paid to acquire inventory, net of vendor consideration and purchase discounts, the cost of equipment added, reconditioning costs, and transportation costs relating to acquiring inventory for sale. We state new and used boat, motor, and trailer inventories at the lower of cost, determined on a specific-identification basis, or market. We state parts and accessories at the lower of cost, determined on an average cost basis, or market. We utilize our historical experience, the aging of the inventories, and our consideration of current market trends as the basis for determining a lower of cost or market valuation allowance. As of September 30, 2015 and June 30, 2016, our lower of cost or market valuation allowance for new and used boat, motor, and trailer inventories was $1.8 million and $2.0 million, respectively. If events occur and market conditions change, causing the fair value to fall below carrying value, the lower of cost or market valuation allowance could increase.
Property Plant and Equipment Impairment or Disposal of Long Lived Assets	FASB Accounting Standards Codification 360-10-40, “Property, Plant, and Equipment - Impairment or Disposal of Long-Lived Assets” (“ASC 360-10-40”), requires that long-lived assets, such as property and equipment and purchased intangibles subject to amortization, be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the asset is measured by comparison of its carrying amount to undiscounted future net cash flows the asset is expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the asset exceeds its fair market value. Estimates of expected future cash flows represent our best estimate based on currently available information and reasonable and supportable assumptions. Any impairment recognized in accordance with ASC 360-10-40 is permanent and may not be restored. Based upon our most recent analysis, which excludes fixed assets classified as held for sale which are recorded at fair value, we believe no impairment of long-lived assets existed as of June 30, 2016.
Income Taxes	We account for income taxes in accordance with FASB Accounting Standards Codification 740, “Income Taxes” (“ASC 740”). Under ASC 740, we recognize deferred tax assets and liabilities for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. We measure deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income in the years in which we expect those temporary differences to be recovered or settled. We record a valuation allowance to reduce our deferred tax assets to the amount expected to be realized by considering all available positive and negative evidence. As of September 30, 2015 and June 30, 2016, we had a valuation allowance on our deferred tax assets of $1.7 million. During the nine months ended June 30, 2016 we recognized an income tax provision of $11.2 million. The effective income tax rate for the nine months ended June 30, 2016 was 39.1%. We had no income tax expense for the nine months ended June 30, 2015 due to the full valuation allowance on deferred tax assets. The majority of the valuation allowance was released in the fourth quarter of fiscal 2015.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.