v3.7.0.1

Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Jan. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Mar. 31, 2016	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 626,801	$ 563,697	$ 576,048	$ 600,603	$ 611,474	$ 573,573	$ 569,134	$ 562,068	$ 2,367,149	$ 2,316,249	$ 2,505,512
Gross profit	167,112	155,884	161,295	166,334	160,541	145,882	154,939	150,415	650,625	611,777	640,911
Operating earnings	51,897	55,023	62,909	66,032	25,953	55,461	59,548	69,037	235,861	209,999	263,381
Net earnings	33,716	37,095	42,793	44,619	5,908	38,214	39,768	47,934	158,223	131,824	181,525
Net earnings attributable to EnerSys stockholders	$ 33,770	$ 36,235	$ 45,636	$ 44,573	$ 9,260	$ 38,478	$ 40,025	$ 48,387	$ 160,214	$ 136,150	$ 181,188
Basic earnings per common share attributable to EnerSys stockholders (usd per share)	$ 0.78	$ 0.83	$ 1.05	$ 1.03	$ 0.21	$ 0.87	$ 0.89	$ 1.09	$ 3.69	$ 3.08	$ 3.97
Diluted earnings per common share attributable to EnerSys stockholders (usd per share)	$ 0.76	$ 0.82	$ 1.04	$ 1.02	$ 0.21	$ 0.86	$ 0.87	$ 1.03	$ 3.64	$ 2.99	$ 3.77

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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