Stockholders' Equity and Noncontrolling Interests - Noncontrolling Interests (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 4,913
Net earnings	$ 71	$ 2,843	(50)	$ 2,797
Pension funded status adjustment, net of tax	338	268	665	549
Total other comprehensive gain (loss), net of tax	32,138	3,198	74,129	(19,191)
Total comprehensive income	75,289	$ 45,991	165,602	68,221
Dividends paid to stockholders			(14,967)	(15,200)
Other, including activity related to equity awards			651	$ 5
Ending balance	$ 4,994		$ 4,994
Dividends declared (in dollars per share)	$ 0.175	$ 0.175	$ 0.35	$ 0.35
Equity Attributable to EnerSys Stockholders
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 1,103,456
Net earnings			91,423
Net unrealized gain on derivative instruments, net of tax			616
Pension funded status adjustment, net of tax			665
Foreign currency translation adjustment			72,817
Total other comprehensive gain (loss), net of tax			74,098
Total comprehensive income			165,521
Purchase of treasury stock including ASR			(121,191)
Dividends paid to stockholders			(14,967)
Other, including activity related to equity awards			2,228
Ending balance	$ 1,135,047		1,135,047
Nonredeemable Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			4,913
Net earnings			50
Net unrealized gain on derivative instruments, net of tax			0
Pension funded status adjustment, net of tax			0
Foreign currency translation adjustment			31
Total other comprehensive gain (loss), net of tax			31
Total comprehensive income			81
Purchase of treasury stock including ASR			0
Dividends paid to stockholders			0
Other, including activity related to equity awards			0
Ending balance	4,994		4,994
Total Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			1,108,369
Net earnings			91,473
Net unrealized gain on derivative instruments, net of tax			616
Pension funded status adjustment, net of tax			665
Foreign currency translation adjustment			72,848
Total other comprehensive gain (loss), net of tax			74,129
Total comprehensive income			165,602
Purchase of treasury stock including ASR			(121,191)
Dividends paid to stockholders			(14,967)
Other, including activity related to equity awards			2,228
Ending balance	$ 1,140,041		$ 1,140,041