Business and Summary of Significant Accounting Policies	6 Months Ended
Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES References herein to “Novelis,” the “Company,” “we,” “our,” or “us” refer to Novelis Inc. and its subsidiaries unless the context specifically indicates otherwise. References herein to “Hindalco” refer to Hindalco Industries Limited, our indirect parent company. Hindalco acquired Novelis in May 2007, through its indirect wholly-owned subsidiary, AV Metals Inc., our direct parent company. Organization and Description of Business We produce aluminum sheet and light gauge products for use in the packaging market, which includes beverage and food can and foil products, as well as for use in the automotive, electronics, architectural, transportation and industrial product markets. We also have recycling operations in many of our plants to recycle post-consumer aluminum, such as used-beverage cans (UBCs) and post-industrial aluminum, such as class scrap. As of September 30, 2014, we had manufacturing operations in eleven countries on four continents: North America, South America, Asia and Europe; through 26 operating facilities, including recycling operations in eleven of these plants. In addition to aluminum rolled products plants, our South American businesses include primary aluminum smelting and power generation facilities. On October 16, 2014, we announced that Novelis will close its remaining smelting facilities by the end of calendar year 2014. Additionally, as of September 30, 2014, the previously announced sales of our power generation assets are pending regulatory approval. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended March 31, 2014 filed with the United States Securities and Exchange Commission (SEC) on May 16, 2014. Management believes that all adjustments necessary for the fair statement of results, consisting of normally recurring items, have been included in the unaudited condensed consolidated financial statements for the interim periods presented. Consolidation Policy Our condensed consolidated financial statements include the assets, liabilities, revenues and expenses of all wholly-owned subsidiaries and majority-owned subsidiaries over which we exercise control and entities in which we have a controlling financial interest or are deemed to be the primary beneficiary. We eliminate all significant intercompany accounts and transactions from our condensed consolidated financial statements. We use the equity method to account for our investments in entities that we do not control, but where we have the ability to exercise significant influence over operating and financial policies. Consolidated “Net income attributable to our common shareholder” includes our share of net income (loss) of these entities. The difference between consolidation and the equity method impacts certain of our financial ratios because of the presentation of the detailed line items reported in the consolidated financial statements for consolidated entities, compared to a two-line presentation of "Investment in and advances to non–consolidated affiliates" and "Equity in net loss of non-consolidated affiliates." Use of Estimates and Assumptions The preparation of our condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires us to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. The principal areas of judgment relate to (1) the fair value of derivative financial instruments; (2) impairment of goodwill; (3) impairment of long lived assets and other intangible assets; (4) impairment of and assessment of consolidation of equity investments; (5) actuarial assumptions related to pension and other postretirement benefit plans; (6) tax uncertainties and valuation allowances; and (7) assessment of loss contingencies, including environmental and litigation liabilities. Future events and their effects cannot be predicted with certainty, and accordingly, our accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of our condensed consolidated financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as our operating environment changes. We evaluate and update our assumptions and estimates on an ongoing basis and may employ outside experts to assist in our evaluations. Actual results could differ from our estimates. Recently Adopted Accounting Standards Effective for the first quarter of fiscal 2015, we adopted Financial Accounting Standards Board ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The amendments in this update provide guidance on the presentation of unrecognized tax benefits and will better reflect the manner in which an entity would settle, at the reporting date, any additional income taxes that would result from the disallowance of a tax position when net operating loss carryforwards, similar tax losses, or tax credit carryforwards exist. The adoption of this standard had an insignificant impact on our condensed consolidated financial position. Recently Issued Accounting Standards In March 2013, the FASB issued ASU No. 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity. The amendments in this update provide clarification regarding the release of a cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. The guidance will be effective for annual reporting periods beginning after December 15, 2014, and interim periods within those annual periods. We will adopt this standard prospectively in our first quarter ending June 30, 2015 and our current accounting policies comply with this guidance. Therefore, this will not have a material impact to our historical financial statements. In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update change the criteria for determining which disposals can be presented as discontinued operations and modify related disclosure requirements. Under the revised standard, a discontinued operation is (1) a component of an entity or group of components that has been disposed of by sale, disposed of other than by sale or is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or (2) an acquired business or nonprofit activity that is classified as held for sale on the date of the acquisition. The guidance is effective for annual periods beginning on or after December 15, 2014 and interim periods within that year. The guidance will be applied prospectively. Early adoption is permitted but only for disposals (or classifications as held for sale) that have not been reported in financial statements previously issued or available for issue. We will adopt this standard prospectively in our first quarter ending June 30, 2015 on future disposals. The accounting treatment and classification of future disposals under this new standard could differ from our current treatment and classification of disposals in our current consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (ASC 606), which, when effective, will supersede the guidance in former ASC 605, Revenue Recognition. The new guidance requires entities to recognize revenue based on 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 is effective for annual periods beginning after December 15, 2016 and interim periods within that year. Early adoption is not permitted. We will adopt this standard in our first quarter ending June 30, 2017. We are currently evaluating the impact of this standard on our consolidated financial position and results of operations. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which requires management of the Company to evaluate whether there is substantial doubt about the Company's ability to continue as a going concern. The amendments in this update are effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. We do not expect this standard to have an impact on the Company's consolidated financial statements upon adoption.

BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

References herein to “Novelis,” the “Company,” “we,” “our,” or “us” refer to Novelis Inc. and its subsidiaries unless the context specifically indicates otherwise. References herein to “Hindalco” refer to Hindalco Industries Limited, our indirect parent company. Hindalco acquired Novelis in May 2007, through its indirect wholly-owned subsidiary, AV Metals Inc., our direct parent company.

Organization and Description of Business

We produce aluminum sheet and light gauge products for use in the packaging market, which includes beverage and food can and foil products, as well as for use in the automotive, electronics, architectural, transportation and industrial product markets. We also have recycling operations in many of our plants to recycle post-consumer aluminum, such as used-beverage cans (UBCs) and post-industrial aluminum, such as class scrap. As of September 30, 2014, we had manufacturing operations in eleven countries on four continents: North America, South America, Asia and Europe; through 26 operating facilities, including recycling operations in eleven of these plants. In addition to aluminum rolled products plants, our South American businesses include primary aluminum smelting and power generation facilities. On October 16, 2014, we announced that Novelis will close its remaining smelting facilities by the end of calendar year 2014. Additionally, as of September 30, 2014, the previously announced sales of our power generation assets are pending regulatory approval.

The accompanying unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended March 31, 2014 filed with the United States Securities and Exchange Commission (SEC) on May 16, 2014. Management believes that all adjustments necessary for the fair statement of results, consisting of normally recurring items, have been included in the unaudited condensed consolidated financial statements for the interim periods presented.

Consolidation Policy

Our condensed consolidated financial statements include the assets, liabilities, revenues and expenses of all wholly-owned subsidiaries and majority-owned subsidiaries over which we exercise control and entities in which we have a controlling financial interest or are deemed to be the primary beneficiary. We eliminate all significant intercompany accounts and transactions from our condensed consolidated financial statements.

We use the equity method to account for our investments in entities that we do not control, but where we have the ability to exercise significant influence over operating and financial policies. Consolidated “Net income attributable to our common shareholder” includes our share of net income (loss) of these entities. The difference between consolidation and the equity method impacts certain of our financial ratios because of the presentation of the detailed line items reported in the consolidated financial statements for consolidated entities, compared to a two-line presentation of "Investment in and advances to non–consolidated affiliates" and "Equity in net loss of non-consolidated affiliates."

Use of Estimates and Assumptions

The preparation of our condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires us to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. The principal areas of judgment relate to (1) the fair value of derivative financial instruments; (2) impairment of goodwill; (3) impairment of long lived assets and other intangible assets; (4) impairment of and assessment of consolidation of equity investments; (5) actuarial assumptions related to pension and other postretirement benefit plans; (6) tax uncertainties and valuation allowances; and (7) assessment of loss contingencies, including environmental and litigation liabilities. Future events and their effects cannot be predicted with certainty, and accordingly, our accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of our condensed consolidated financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as our operating environment changes. We evaluate and update our assumptions and estimates on an ongoing basis and may employ outside experts to assist in our evaluations. Actual results could differ from our estimates.

Recently Adopted Accounting Standards

Effective for the first quarter of fiscal 2015, we adopted Financial Accounting Standards Board ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The amendments in this update provide guidance on the presentation of unrecognized tax benefits and will better reflect the manner in which an entity would settle, at the reporting date, any additional income taxes that would result from the disallowance of a tax position when net operating loss carryforwards, similar tax losses, or tax credit carryforwards exist. The adoption of this standard had an insignificant impact on our condensed consolidated financial position.

Recently Issued Accounting Standards

In March 2013, the FASB issued ASU No. 2013-05, Foreign Currency Matters (Topic 830): Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity. The amendments in this update provide clarification regarding the release of a cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. The guidance will be effective for annual reporting periods beginning after December 15, 2014, and interim periods within those annual periods. We will adopt this standard prospectively in our first quarter ending June 30, 2015 and our current accounting policies comply with this guidance. Therefore, this will not have a material impact to our historical financial statements.

In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update change the criteria for determining which disposals can be presented as discontinued operations and modify related disclosure requirements. Under the revised standard, a discontinued operation is (1) a component of an entity or group of components that has been disposed of by sale, disposed of other than by sale or is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or (2) an acquired business or nonprofit activity that is classified as held for sale on the date of the acquisition. The guidance is effective for annual periods beginning on or after December 15, 2014 and interim periods within that year. The guidance will be applied prospectively. Early adoption is permitted but only for disposals (or classifications as held for sale) that have not been reported in financial statements previously issued or available for issue. We will adopt this standard prospectively in our first quarter ending June 30, 2015 on future disposals. The accounting treatment and classification of future disposals under this new standard could differ from our current treatment and classification of disposals in our current consolidated financial statements.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (ASC 606), which, when effective, will supersede the guidance in former ASC 605, Revenue Recognition. The new guidance requires entities to recognize revenue based on 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 is effective for annual periods beginning after December 15, 2016 and interim periods within that year. Early adoption is not permitted. We will adopt this standard in our first quarter ending June 30, 2017. We are currently evaluating the impact of this standard on our consolidated financial position and results of operations.

In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which requires management of the Company to evaluate whether there is substantial doubt about the Company's ability to continue as a going concern. The amendments in this update are effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. We do not expect this standard to have an impact on the Company's consolidated financial statements upon adoption.