Nature of Business and Basis of Presentation	9 Months Ended
Jul. 02, 2022
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 ("BBBC"), 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 BBBC’s sales are made to an independent dealer network, which in turn sells buses to ultimate end users. References in these notes to condensed consolidated financial statements to “Blue Bird,” the “Company,” “we,” “our,” or “us” relate to Blue Bird Corporation and its wholly-owned subsidiaries, unless the context specifically indicates otherwise. We are headquartered in Macon, Georgia. 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 accounting principles generally accepted in the United States of America (“U.S. GAAP”) 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. The fiscal years ending October 1, 2022 ("fiscal 2022") and ended October 2, 2021 ("fiscal 2021") consist or consisted of 52 weeks. The third quarters of fiscal 2022 and fiscal 2021 both included 13 weeks. The nine month periods in fiscal 2022 and 2021 both included 39 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 U.S. GAAP for complete financial statements. The Condensed Consolidated Balance Sheet data as of October 2, 2021 was derived from the Company’s audited financial statements but does not include all disclosures required by U.S. GAAP. For additional information, including the Company’s significant accounting policies, refer to the consolidated financial statements and related footnotes as of and for the fiscal year ended October 2, 2021 as set forth in the Company's fiscal 2021 Form 10-K filed on December 15, 2021. Impacts of COVID-19 and Russia's Invasion of Ukraine on our Business Towards the end of our second quarter of the fiscal year that ended October 3, 2020 ("fiscal 2020") and continuing through the third quarter of fiscal 2022, the novel coronavirus known as "COVID-19" spread throughout the world, resulting in a global pandemic. The pandemic has significantly impacted our financial results from the second half of fiscal 2020, continuing through the third quarter of fiscal 2022, causing, among other matters, reduced demand for school buses and major supply chain disruptions during portions of this period of time. Additionally, Russian military forces launched a large-scale invasion of Ukraine on February 24, 2022. While the Company has no assets or customers in either of these countries, this military conflict significantly impacted our financial results during the third quarter of fiscal 2022, primarily in an indirect manner since the Company does not sell to customers located in, or source goods directly from, either country. Specifically, it has contributed to increased a) costs charged by suppliers for the purchase of inventory that is at least partially dependent on resources originating from either of the countries and b) freight costs, both of which negatively impacted the gross profit recognized on sales during the third quarter of fiscal 2022. The continuing development and fluidity of the pandemic and military conflict in Ukraine and their trailing impacts preclude any prediction as to the ultimate severity of the adverse impacts on our business, financial condition, results of operations, and liquidity. Use of Estimates and Assumptions The preparation of financial statements in accordance with 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; the allowance for doubtful accounts; potential impairment of long-lived assets, goodwill and intangible assets; and the accounting for self-insurance reserves, warranty reserves, pension obligations, income taxes, environmental liabilities and contingencies. Future events, including the extent and duration of COVID-19 related economic impacts, 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.

Blue Bird Body Company ("BBBC"), 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 BBBC’s sales are made to an independent dealer network, which in turn sells buses to ultimate end users. References in these notes to condensed consolidated financial statements to “Blue Bird,” the “Company,” “we,” “our,” or “us” relate to Blue Bird Corporation and its wholly-owned subsidiaries, unless the context specifically indicates otherwise. We are headquartered in Macon, Georgia.

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 accounting principles generally accepted in the United States of America (“U.S. GAAP”) 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. The fiscal years ending October 1, 2022 ("fiscal 2022") and ended October 2, 2021 ("fiscal 2021") consist or consisted of 52 weeks. The third quarters of fiscal 2022 and fiscal 2021 both included 13 weeks. The nine month periods in fiscal 2022 and 2021 both included 39 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 U.S. GAAP for complete financial statements.

The Condensed Consolidated Balance Sheet data as of October 2, 2021 was derived from the Company’s audited financial statements but does not include all disclosures required by U.S. GAAP. For additional information, including the Company’s significant accounting policies, refer to the consolidated financial statements and related footnotes as of and for the fiscal year ended October 2, 2021 as set forth in the Company's fiscal 2021 Form 10-K filed on December 15, 2021.

Towards the end of our second quarter of the fiscal year that ended October 3, 2020 ("fiscal 2020") and continuing through the third quarter of fiscal 2022, the novel coronavirus known as "COVID-19" spread throughout the world, resulting in a global pandemic. The pandemic has significantly impacted our financial results from the second half of fiscal 2020, continuing through the third quarter of fiscal 2022, causing, among other matters, reduced demand for school buses and major supply chain disruptions during portions of this period of time.

Additionally, Russian military forces launched a large-scale invasion of Ukraine on February 24, 2022. While the Company has no assets or customers in either of these countries, this military conflict significantly impacted our financial results during the third quarter of fiscal 2022, primarily in an indirect manner since the Company does not sell to customers located in, or source goods directly from, either country. Specifically, it has contributed to increased a) costs charged by suppliers for the purchase of inventory that is at least partially dependent on resources originating from either of the countries and b) freight costs, both of which negatively impacted the gross profit recognized on sales during the third quarter of fiscal 2022.

The continuing development and fluidity of the pandemic and military conflict in Ukraine and their trailing impacts preclude any prediction as to the ultimate severity of the adverse impacts on our business, financial condition, results of operations, and liquidity.

The preparation of financial statements in accordance with 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