Business Combinations - Additional Information (Detail) - USD ($)								3 Months Ended	12 Months Ended
	Feb. 10, 2023	Nov. 29, 2022	Sep. 01, 2022	Jul. 01, 2022	Dec. 13, 2021	Nov. 30, 2021	Sep. 30, 2021	Aug. 31, 2023	May 31, 2024	May 31, 2023	May 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Cash consideration for purchase of business		$ 37,000		$ 1,310,000
Purchase price allocation for intangible assets				620,000
Adjustments to intangible assets								$ 100,000
Cash payable to former owner for purchase of business				234,000
Payments to Acquire Businesses, Net of Cash Acquired									$ 0	$ (11,721,000)	$ 38,745,000
Maximum potential Payments	$ 8,500,000						$ 6,500,000		0
Maximum future royalty payments							14,500,000
Loss on performance milestone liability									300,000
Performance milestone liability										300,000
Other non-current liabilities	930,000
Stock Issued During Period, Value, Acquisitions										2,262,841,000
Goodwill									2,135,632,000	2,137,496,000	142,704,000
Operating income (loss)									58,663,000	37,515,000	58,618,000
Amortization expense for intangible assets									94,946,000	71,085,000	9,600,000
CAPInnoVet, Inc
Business Acquisition [Line Items]
Purchase price allocation for accounts receivable							308,000
Purchase price allocation for inventory							531,000
Purchase price allocation for Prepaid Expenses							296,000
Purchase price allocation for other current liabilities							84,000
Purchase price allocation for long-term liabilities							6,500,000
Purchase price allocation for intangible assets							19,200,000
Purchase price allocation for accounts payable							120,000
Payments to Acquire Businesses, Net of Cash Acquired							$ 17,900,000
Delf (UK) Ltd
Business Acquisition [Line Items]
Cash consideration for purchase of business						$ 9,500,000
Purchase price allocation for accounts receivable						1,059,000
Purchase price allocation for inventory						972,000
Purchase price allocation for land, property and equipment						152,000
Purchase price allocation for Prepaid Expenses						31,000
Purchase price allocation for other current liabilities						378,000
Purchase price allocation for deferred tax liability						780,000
Purchase price allocation for intangible assets						3,100,000
Purchase price allocation for accounts payable						$ 497,000
Genetic Veterinary Services, Inc
Business Acquisition [Line Items]
Purchase price allocation for accounts receivable												$ 38,000
Purchase price allocation for inventory												292,000
Purchase price allocation for land, property and equipment												399,000
Purchase price allocation for Prepaid Expenses												54,000
Purchase price allocation for other current liabilities												321,000
Unearned revenue liability												1,900,000
Purchase price allocation for intangible assets												5,500,000
Purchase price allocation for accounts payable												$ 325,000
Payments to Acquire Businesses, Net of Cash Acquired					$ 11,300,000
Thaineo Biotech Co Ltd
Business Acquisition [Line Items]
Business combination, consideration transferred				$ 1,581,000
Corvium Inc
Business Acquisition [Line Items]
Purchase price allocation for land, property and equipment	13,000
Purchase price allocation for Prepaid Expenses	66,000
Unearned revenue liability	1,827,000
Purchase price allocation for intangible assets	10,280,000
Business combination, consideration transferred	24,067,000
Cash held in escrow	9,004,000
Escrow balance released								$ 8,000,000
Other non-current liabilities	930,000
Goodwill	$ 16,884,000
3M Food Safety Transaction
Business Acquisition [Line Items]
Purchase price allocation for inventory			$ 18,403,000
Purchase price allocation for land, property and equipment			25,832,000
Purchase price allocation for deferred tax liability			352,636,000
Purchase price allocation for intangible assets			1,559,805,000
Other non-current liabilities			$ 2,832,000
Number of shares issued in business acquisitions			108,269,946
Stock Issued During Period, Value, Acquisitions			$ 2,200,000,000
Goodwill			1,974,870,000						1,970,000,000
Business acquisition, goodwill, not deductible for tax purposes									$ 1,920,000,000
Revenues										919,959,000	910,978,000
Operating income (loss)										$ 44,373,000	$ 42,258,000
Non-cash consideration			3,200,000,000
3M Food Safety Transaction | Garden Spinco
Business Acquisition [Line Items]
Non-cash consideration by additional financing			$ 1,000,000,000
3M Food Safety Transaction | Postmerger Neogen Corp | PreMerger Neogen Shareholders
Business Acquisition [Line Items]
Minority interest ownership percentage by Noncontrolling owners			49.90%
3M Food Safety Transaction | Postmerger Neogen Corp | Garden Spinco
Business Acquisition [Line Items]
Minority interest ownership percentage by Parent			50.10%