Significant accounting policies (Policies)	3 Months Ended
Significant accounting policies (Policies)	Dec. 31, 2013
Significant accounting policies [Abstract]
Basis of presentation	Basis of presentation: The accompanying unaudited condensed consolidated financial statements have been derived from unaudited interim financial information prepared in accordance with the rules and regulations of the SEC for quarterly financial statements. Certain information and note disclosures normally included in financial statements prepared in accordance the U.S. generally accepted accounting principles ("GAAP") have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information presented not misleading. The interim financial statements of the Company, in the opinion of management, include all normal and recurring adjustments necessary for a fair presentation of results as of the dates and for the periods covered by the interim financial statements. Operating results for the three months ended December 31, 2013 are not necessarily indicative of the results that may be expected for the entire fiscal year. The accompanying unaudited condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern. These condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2013. The accompanying condensed consolidated balance sheet at September 30, 2013 has been derived from the audited financial statements at that date, but does not include all information and footnotes required by GAAP for complete financial statements.
Principles of consolidation	Principles of consolidation: The unaudited condensed consolidated financial statements include those of Biovest Europe, Limited and Viracell Advanced Products, LLC. Biovest Europe Limited is a wholly-owned subsidiary of the Company which was incorporated in the United Kingdom on June 29, 2011. Viracell Advanced Products, LLC, is an 85% owned subsidiary of the Company which was incorporated in the State of Texas on July 18, 2013. All significant inter-company balances and transactions have been eliminated.
Accounting for reorganization proceedings	Accounting for reorganization proceedings: On the Effective Date, the terms of Biovest's confirmed Plan of Reorganization eliminated approximately $44 million in secured and unsecured debt in exchange for new common shares of Biovest. Also upon the Effective Date, all previously-existing equity interests in Biovest were canceled and extinguished. As a result of the recapitalization of the Company, Biovest was required to adopt fresh-start accounting in accordance with ASC Topic 852 - Reorganizations based upon the fact that; (a) total post-petition liabilities and allowed claims exceeded the reorganization value; and (b) pre-petition shareholders received less than 50% of the new common shares issued under the reorganization plan, thereby resulting in a substantive change in control. Biovest applied fresh start accounting on July 1, 2013 (the "Convenience Date") after concluding that the operating results between the Convenience Date and the Effective Date did not result in a material difference. Given that the reorganization and adoption of fresh-start accounting resulted in a new entity for financial reporting purposes, Biovest is referred to as the "Predecessor Company" for all periods preceding the Convenience Date, and the "Successor Company" for all periods subsequent to the Convenience Date. Overall, the implementation of fresh-start accounting resulted in: (i) a comprehensive revaluation of the Predecessor Company's assets and liabilities to their estimated fair values and; (ii) the elimination of the Predecessor Company's accumulated deficit and additional paid-in capital. Due to the fact that these changes are material to Biovest's consolidated financial statements, the results of the Successor Company may not be comparable in certain respects to those of the Predecessor Company.
Use of estimates in the preparation of financial statements	Use of estimates in the preparation of financial statements: The preparation of condensed consolidated financial statements in conformity with GAAP require management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures about contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Fair value of financial assets and liabilities	Fair value of financial assets and liabilities: Both the Predecessor Company and Successor Company measure the fair value of financial assets and liabilities in accordance with GAAP which defines fair value, establishes a framework for measuring fair value, and requires certain disclosures about fair value measurements. GAAP defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. GAAP also establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. GAAP describes three levels of inputs that may be used to measure fair value: Level 1 - quoted prices in active markets for identical assets or liabilities Level 2 - quoted prices for similar assets and liabilities in active markets or inputs that are observable Level 3 - inputs that are unobservable (for example cash flow modeling inputs based on assumptions)
Shipping and handling costs	Shipping and handling costs: Shipping and handling costs are included as a component of cost of revenue in the accompanying condensed consolidated statements of operations.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In July 2013, the FASB issued guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This guidance requires the unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset. When a deferred tax asset is not available, or the asset is not intended to be used for this purpose, an entity should present the unrecognized tax benefit in the financial statements as a liability. The guidance will become effective for us at the beginning of our second quarter of fiscal 2014. We do not expect the adoption of this guidance will have a material impact on our financial statements. In January 2013, the FASB issued guidance clarifying the scope of disclosure requirements for offsetting assets and liabilities. The amended guidance limits the scope of balance sheet offsetting disclosures to derivatives, repurchase agreements, and securities lending transactions to the extent that they are offset in the financial statements or subject to an enforceable master netting arrangement or similar agreement. The guidance became effective for us on October 1, 2013. The adoption of this guidance has not had a material impact on our financial statements.

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02, 03

-Article 3A

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-Section 45

-URI http://asc.fasb.org/section&trid=2197723

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-URI http://asc.fasb.org/subtopic&trid=2197087

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section S99

-Paragraph 2

-Subparagraph (SX 210.3A-02)

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Publisher FASB

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-URI http://asc.fasb.org/extlink&oid=18733093&loc=d3e5614-111684

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph k

-Article 1

+ Details

- Definition

Disclosure of accounting policy for the classification of shipping and handling costs, including whether the costs are included in cost of sales or included in other income statement accounts. If shipping and handling fees are significant and are not included in cost of sales, disclosure includes both the amounts of such costs and the line item on the income statement which includes such costs.

+ References+ Details

BIOVEST INTERNATIONAL INC 10-Q