Document and Entity Information
| Document and Entity Information | Sep. 19, 2019 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001289308 |
| Document Type | 8-K |
| Document Period End Date | Sep. 19, 2019 |
| Entity Registrant Name | EnerSys |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-32253 |
| Entity Tax Identification Number | 23-3058564 |
| Entity Address, Address Line One | 2366 Bernville Road |
| Entity Address, City or Town | Reading |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19605 |
| City Area Code | (610) |
| Local Phone Number | 208-1991 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value per share |
| Trading Symbol | ENS |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |