Segment Information (Detail) - USD ($) $ in Thousands		12 Months Ended
		May 31, 2024	May 31, 2023	May 31, 2022
Segment Reporting Information [Line Items]
Total revenues to external customers		$ 924,222	$ 822,447	$ 527,159
Operating income (loss)		58,663	37,515	58,618
Depreciation and amortization		116,717	88,377	23,694
Interest expense		73,394	55,961	72
Total Assets		4,548,833	4,554,432	992,929
Expenditures for long-lived assets		111,421	65,757	24,781
Operating Segments | Food Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		655,341	546,797	259,979
Operating income (loss)		82,446	60,414	38,581
Depreciation and amortization		102,328	76,841	13,386
Total Assets		4,035,257	3,970,356	304,461
Expenditures for long-lived assets		93,036	52,169	7,842
Operating Segments | Animal Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		268,881	275,650	267,180
Operating income (loss)		39,320	43,332	52,546
Depreciation and amortization		14,389	11,536	10,308
Total Assets		342,640	338,507	307,417
Expenditures for long-lived assets		18,385	13,588	16,939
Corporate and Eliminations | Operating Segments
Segment Reporting Information [Line Items]
Operating income (loss)	[1]	(63,103)	(66,231)	(32,509)
Interest expense	[1]	73,394	55,961	72
Total Assets	[1]	$ 170,936	$ 245,569	$ 381,051

[1] Includes corporate assets, including cash and cash equivalents, marketable securities, current and deferred tax accounts, and overhead expenses not allocated to specific business segments. Also includes the elimination of intersegment transactions.