Nature of Business and Basis of Presentation	3 Months Ended
Dec. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Nature of Business Blue Bird Body Company, a wholly-owned subsidiary of Blue Bird Corporation, was incorporated in 1958 and has manufactured, assembled and sold school buses to a variety of municipal, federal and commercial customers since 1927. The majority of Blue Bird’s sales are made to an independent distributor network, which in turn sells buses to ultimate end users. We are headquartered in Macon, Georgia. References in these notes to financial statements to “Blue Bird”, the “Company,” “we,” “our,” or “us” refer to Blue Bird Corporation and its wholly-owned subsidiaries, unless the context specifically indicates otherwise. Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company transactions and accounts have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial reporting and Article 8 of Regulation S-X. The Company’s fiscal year ends on the Saturday closest to September 30 with its quarters consisting of thirteen weeks in most years. In fiscal year 2019, there is a total of 52 weeks. For fiscal years 2019 and 2018, the first quarters both included 13 weeks. In the opinion of management, all adjustments considered necessary for a fair presentation of financial results have been made. Such adjustments consist of only those of a normal recurring nature. Operating results for any interim period are not necessarily indicative of the results that may be expected for the entire year. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. The Condensed Consolidated Balance Sheet data as of September 29, 2018 was derived from the Company’s audited financial statements but do not include all disclosures required by generally accepted accounting principles. For additional information, including the Company’s significant accounting policies, refer to the consolidated financial statements and related footnotes for the fiscal year ended September 29, 2018 as set forth in the Company's 2018 Form 10-K filed on December 12, 2018. Preferred Stock Conversion On November 13, 2018, the Company converted all remaining outstanding shares of Preferred Stock, and issued 799,615 shares of Common Stock. There were no dividends paid with the conversion. Use of Estimates and Assumptions The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions. At the date of the financial statements, these estimates and assumptions affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities, and during the reporting period, these estimates and assumptions affect the reported amounts of revenues and expenses. For example, significant management judgments are required in determining excess, obsolete, or unsalable inventory, allowance for doubtful accounts, potential impairment of long-lived assets, goodwill and intangibles, the accounting for self-insurance reserves, warranty reserves, pension obligations, income taxes, environmental liabilities and contingencies. Future events and their effects cannot be predicted with certainty, and, accordingly, the Company’s accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of the Company’s condensed consolidated financial statements may change as new events occur, as more experience is acquired, as additional information is obtained and as the Company’s operating environment changes. The Company evaluates and updates its assumptions and estimates on an ongoing basis and may employ outside experts to assist in the Company’s evaluations. Actual results could differ from the estimates that the Company has used.

1. Nature of Business and Basis of Presentation

Nature of Business

Blue Bird Body Company, a wholly-owned subsidiary of Blue Bird Corporation, was incorporated in 1958 and has manufactured, assembled and sold school buses to a variety of municipal, federal and commercial customers since 1927. The majority of Blue Bird’s sales are made to an independent distributor network, which in turn sells buses to ultimate end users. We are headquartered in Macon, Georgia. References in these notes to financial statements to “Blue Bird”, the “Company,” “we,” “our,” or “us” refer to Blue Bird Corporation and its wholly-owned subsidiaries, unless the context specifically indicates otherwise.

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company transactions and accounts have been eliminated in consolidation.

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial reporting and Article 8 of Regulation S-X. The Company’s fiscal year ends on the Saturday closest to September 30 with its quarters consisting of thirteen weeks in most years. In fiscal year 2019, there is a total of 52 weeks. For fiscal years 2019 and 2018, the first quarters both included 13 weeks.

In the opinion of management, all adjustments considered necessary for a fair presentation of financial results have been made. Such adjustments consist of only those of a normal recurring nature. Operating results for any interim period are not necessarily indicative of the results that may be expected for the entire year. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.

The Condensed Consolidated Balance Sheet data as of September 29, 2018 was derived from the Company’s audited financial statements but do not include all disclosures required by generally accepted accounting principles. For additional information, including the Company’s significant accounting policies, refer to the consolidated financial statements and related footnotes for the fiscal year ended September 29, 2018 as set forth in the Company's 2018 Form 10-K filed on December 12, 2018.

Preferred Stock Conversion

On November 13, 2018, the Company converted all remaining outstanding shares of Preferred Stock, and issued 799,615 shares of

Common Stock. There were no dividends paid with the conversion.

Use of Estimates and Assumptions

The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions. At the date of the financial statements, these estimates and assumptions affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities, and during the reporting period, these estimates and assumptions affect the reported amounts of revenues and expenses. For example, significant management judgments are required in determining excess, obsolete, or unsalable inventory, allowance for doubtful accounts, potential impairment of long-lived assets, goodwill and intangibles, the accounting for self-insurance reserves, warranty reserves, pension obligations, income taxes, environmental liabilities and contingencies. Future events and their effects cannot be predicted with certainty, and, accordingly, the Company’s accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of the Company’s condensed consolidated financial statements may change as new events occur, as more experience is acquired, as additional information is obtained and as the Company’s operating environment changes. The Company evaluates and updates its assumptions and estimates on an ongoing basis and may employ outside experts to assist in the Company’s evaluations. Actual results could differ from the estimates that the Company has used.