Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Contra-Equity	Total EnerSys Stockholders’ Equity	Non- redeemable Non- Controlling Interests
Beginning Balance at Mar. 31, 2017	$ 1,108,369	$ 0	$ 544	$ 464,092	$ (439,800)	$ 1,231,444	$ (152,824)	$ 0	$ 1,103,456	$ 4,913
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	19,453			19,453					19,453
Shares issued under equity awards (taxes paid related to net share settlement of equity awards), net	(6,531)		2	(6,533)					(6,531)
Other	(539)			(402)		(137)			(539)
Purchase of common stock	(121,191)				(121,191)				(121,191)
Net earnings	119,833					119,594			119,594	239
Dividends ($0.70 per common share)	(29,674)			678		(30,352)			(29,674)
Other comprehensive income:
Pension funded status adjustment, (net of tax (expense) benefit)	3,052						3,052		3,052
Net unrealized gain (loss) on derivative instruments (net of tax (benefit) expense)	(5,400)						(5,400)		(5,400)
Foreign currency translation adjustment (excludes losses related to redeemable noncontrolling interests)	113,739						113,455		113,455	284
Ending Balance at Mar. 31, 2018	1,201,111	0	546	477,288	(560,991)	1,320,549	(41,717)	0	1,195,675	5,436
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	22,608			22,608					22,608	0
Exercise of stock options	9,048		2	9,046					9,048
Shares issued under equity awards (taxes paid related to net share settlement of equity awards), net	(3,630)			(3,630)					(3,630)
Other	(141)			(141)		0			(141)
Purchase of common stock	(56,436)				(56,436)				(56,436)
Reissuance of treasury stock, on LIFO basis, towards Alpha purchase consideration	93,268			6,805	86,463				93,268
Reissuance of treasury stock towards employee stock purchase plan	204				204				204
Contra equity - adjustment to indemnification receivable for acquisition related tax liability	(7,840)							(7,840)	(7,840)
Net earnings	160,627					160,239			160,239	388
Dividends ($0.70 per common share)	(29,743)			720		(30,463)			(29,743)
Dissolution of joint venture	(1,511)									(1,511)
Other comprehensive income:
Pension funded status adjustment, (net of tax (expense) benefit)	1,712						1,712		1,712
Net unrealized gain (loss) on derivative instruments (net of tax (benefit) expense)	3,295						3,295		3,295
Foreign currency translation adjustment (excludes losses related to redeemable noncontrolling interests)	(106,555)						(105,972)		(105,972)	(583)
Ending Balance at Mar. 31, 2019	1,286,017	0	548	512,696	(530,760)	1,450,325	(142,682)	(7,840)	1,282,287	3,730
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	20,780			20,780					20,780
Exercise of stock options	1,417		3	1,414					1,417
Shares issued under equity awards (taxes paid related to net share settlement of equity awards), net	(6,393)			(6,393)					(6,393)
Other	(80)			(80)					(80)
Purchase of common stock	(34,561)				(34,561)				(34,561)
Reissuance of treasury stock towards employee stock purchase plan	872			(73)	945				872
Contra equity - adjustment to indemnification receivable for acquisition related tax liability	1,116							1,116	1,116	0
Net earnings	137,116					137,116			137,116	0
Dividends ($0.70 per common share)	(29,705)			756		(30,461)			(29,705)
Other comprehensive income:
Pension funded status adjustment, (net of tax (expense) benefit)	(2,003)						(2,003)		(2,003)
Net unrealized gain (loss) on derivative instruments (net of tax (benefit) expense)	(5,793)						(5,793)		(5,793)
Foreign currency translation adjustment (excludes losses related to redeemable noncontrolling interests)	(64,721)						(64,528)		(64,528)	(193)
Ending Balance at Mar. 31, 2020	$ 1,304,062	$ 0	$ 551	$ 529,100	$ (564,376)	$ 1,556,980	$ (215,006)	$ (6,724)	$ 1,300,525	$ 3,537