Basis of Presentation (Policies)	6 Months Ended
Basis of Presentation (Policies)	Oct. 03, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated condensed financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments except those otherwise described herein) considered necessary for a fair presentation have been included, unless otherwise disclosed. Operating results for the three and six months ended October 3, 2021 are not necessarily indicative of the results that may be expected for the fiscal year ending March 31, 2022. The Consolidated Condensed Balance Sheet at March 31, 2021 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. The financial statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company’s 2021 Annual Report on Form 10-K (SEC File No. 001-32253), which was filed on May 26, 2021 (the “2021 Annual Report”). EnerSys (the “Company”) reports interim financial information for 13-week periods, except for the first quarter, which always begins on April 1, and the fourth quarter, which always ends on March 31. The four quarters in fiscal 2022 end on July 4, 2021, October 3, 2021, January 2, 2022, and March 31, 2022, respectively. The four quarters in fiscal 2021 ended on July 5, 2020, October 4, 2020, January 3, 2021, and March 31, 2021, respectively. The consolidated condensed financial statements include the accounts of the Company and its wholly-owned subsidiaries and any partially owned subsidiaries that the Company has the ability to control. All intercompany transactions and balances have been eliminated in consolidation.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740)”: Simplifying the Accounting for Income Taxes, which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. The guidance is effective for fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company adopted the standard in the first quarter of fiscal 2022 and the adoption did not have a material impact on the Company's consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates and assumptions take into account historical and forward looking factors that the Company believes are reasonable, including, but not limited to, the potential impacts arising from the coronavirus pandemic including its variants (“COVID-19”) and public and private sector policies and initiatives aimed at reducing its transmission. As the extent and duration of the impacts of COVID-19 remain unclear, the Company’s estimates and assumptions may evolve as conditions change. Actual results could differ significantly from those estimates. Examples of significant estimates include the allowance for credit losses, the recoverability of property, plant and equipment, the incremental borrowing rate for lease liabilities, the recoverability of intangible assets and other long-lived assets, fair value measurements, including those related to financial instruments, goodwill and intangible assets, valuation allowances on tax assets, pension and postretirement benefit obligations, contingencies and the identification and valuation of assets acquired and liabilities assumed in connection with business combinations.