Consolidated Statements of Income - USD ($)	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 3,087,868,000	$ 2,808,017,000	$ 2,581,891,000
Cost of goods sold	2,301,148,000	2,104,612,000	1,920,030,000
Inventory step up to fair value relating to acquisitions and exit activities	1,854,000	10,379,000	3,457,000
Gross profit	784,866,000	693,026,000	658,404,000
Operating expenses	529,643,000	441,415,000	382,077,000
Restructuring and other exit charges	20,766,000	34,709,000	5,481,000
Impairment of goodwill	39,713,000	0	0
Impairment of indefinite-lived intangibles	4,549,000	0	0
Legal proceedings charge, net	0	(4,437,000)	0
Operating earnings	190,195,000	212,465,000	270,846,000
Interest expense	43,673,000	30,868,000	25,001,000
Other (income) expense, net	(415,000)	(614,000)	7,519,000
Earnings before income taxes	146,937,000	182,211,000	238,326,000
Income tax expense	9,821,000	21,584,000	118,493,000
Net earnings	137,116,000	160,627,000	119,833,000
Net earnings attributable to noncontrolling interests	0	388,000	239,000
Net earnings attributable to EnerSys stockholders	$ 137,116,000	$ 160,239,000	$ 119,594,000
Net earnings per common share attributable to EnerSys stockholders:
Basic (usd per share)	$ 3.23	$ 3.79	$ 2.81
Diluted (usd per share)	3.20	3.73	2.77
Dividends per common share (usd per share)	$ 0.70	$ 0.70	$ 0.70
Weighted-average number of common shares outstanding:
Basic (in shares)	42,411,834	42,335,023	42,612,036
Diluted (in shares)	42,896,775	43,008,952	43,119,856