Segment Information and Geographic Data - Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Feb. 29, 2024		Feb. 28, 2023		Feb. 29, 2024		Feb. 28, 2023		May 31, 2023
Segment Reporting Information [Line Items]
Total revenues to external customers		$ 228,812		$ 218,255		$ 687,428		$ 580,637
Operating income (loss)		12,023		15,684		45,623		14,090
Total Assets		4,582,492		4,508,764		4,582,492		4,508,764		$ 4,554,432
Operating Segments | Food Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		157,754		151,542		488,435		377,528
Operating income (loss)		15,915		11,011		62,485		41,053
Total Assets		4,071,831		3,975,921		4,071,831		3,975,921
Operating Segments | Animal Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		71,058		66,713		198,993		203,109
Operating income (loss)		14,781		10,752		30,876		35,439
Total Assets		344,205		349,628		344,205		349,628
Product Revenues
Segment Reporting Information [Line Items]
Total revenues to external customers		202,178		190,688		610,448		500,797
Product Revenues | Operating Segments | Food Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		149,709		144,843		464,973		356,856
Product Revenues | Operating Segments | Animal Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		52,469		45,845		145,475		143,941
Service Revenues
Segment Reporting Information [Line Items]
Total revenues to external customers		26,634		27,567		76,980		79,840
Service Revenues | Operating Segments | Food Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		8,045		6,699		23,462		20,672
Service Revenues | Operating Segments | Animal Safety
Segment Reporting Information [Line Items]
Total revenues to external customers		18,589		20,868		53,518		59,168
Corporate and Eliminations | Operating Segments
Segment Reporting Information [Line Items]
Total revenues to external customers		0	[1]	0	[1]	0	[2]	0	[2]
Operating income (loss)		(18,673)	[1]	(6,079)	[1]	(47,738)	[2]	(62,402)	[2]
Total Assets	[1]	166,456		183,215		166,456		183,215
Corporate and Eliminations | Product Revenues | Operating Segments
Segment Reporting Information [Line Items]
Total revenues to external customers		0	[1]	0	[1]	0	[2]	0	[2]
Corporate and Eliminations | Service Revenues | Operating Segments
Segment Reporting Information [Line Items]
Total revenues to external customers		$ 0	[1]	$ 0	[1]	$ 0	[2]	$ 0	[2]

[1] Includes corporate assets, consisting principally of 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.

[2] Includes the elimination of intersegment transactions.