Net Income (Loss) Per Share - Calculation of Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Earnings Per Share [Line Items]
Numerator for basic and diluted net income (loss) per share - Net income (loss) attributable to Neogen	$ (41,841)	$ 10,828	$ (36,632)	$ 27,905
Denominator for basic net income (loss) per share - Weighted average shares	216,134	107,641	161,690	107,565
Effect of dilutive stock options and RSUs		481		534
Denominator for diluted net income (loss) per share	216,134	108,122	161,690	108,099
Net income (loss) per share:
Basic	$ (0.19)	$ 0.1	$ (0.23)	$ 0.26
Diluted	$ (0.19)	$ 0.1	$ (0.23)	$ 0.26