Earnings Per Share - (Reconciliation from Basic to Diluted Average Common Shares) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 04, 2020	Sep. 30, 2019	Oct. 04, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net earnings attributable to EnerSys stockholders		$ 62,698	$ 70,914	$ 111,334
Basic weighted-average number of common shares outstanding (in shares)	42,521,659	42,392,039	42,453,774	42,524,189
Common shares from exercise and lapse of equity awards, net of shares assumed reacquired (in shares)	565,796	316,043	555,981	389,069
Diluted weighted-average number of common shares outstanding (in shares)	43,087,455	42,708,082	43,009,755	42,913,258
Basic earnings per common share attributable to EnerSys stockholders (in dollars per share)	$ 0.84	$ 1.48	$ 1.67	$ 2.62
Diluted earnings per common share attributable to EnerSys stockholders (in dollars per share)	$ 0.83	$ 1.47	$ 1.65	$ 2.59
Anti-dilutive equity awards not included in diluted weighted-average common shares (in shares)	149,616	1,005,326	267,940	831,068
Redeemable Noncontrolling Interest [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net earnings attributable to EnerSys stockholders	$ 35,731