Revenue Recognition - Summary of Disaggregated Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Disaggregation of Revenue [Line Items]
Total Revenues	$ 230,033	$ 130,517	$ 362,382	$ 258,822
Food Safety
Disaggregation of Revenue [Line Items]
Total Revenues	161,343	67,132	225,986	129,854
Food Safety | Natural Toxins, Allergens & Drug Residues
Disaggregation of Revenue [Line Items]
Total Revenues	22,251	21,028	42,038	41,432
Food Safety | Bacterial & General Sanitation
Disaggregation of Revenue [Line Items]
Total Revenues	41,121	12,252	51,849	23,421
Food Safety | Culture Media & Other
Disaggregation of Revenue [Line Items]
Total Revenues	82,084	19,935	101,338	37,981
Food Safety | Rodent Control, Insect Control & Disinfectants
Disaggregation of Revenue [Line Items]
Total Revenues	10,377	8,232	19,952	15,882
Food Safety | Genomics Services
Disaggregation of Revenue [Line Items]
Total Revenues	5,510	5,685	10,809	11,138
Animal Safety
Disaggregation of Revenue [Line Items]
Total Revenues	68,690	63,385	136,396	128,968
Animal Safety | Rodent Control, Insect Control & Disinfectants
Disaggregation of Revenue [Line Items]
Total Revenues	20,665	18,269	42,879	40,418
Animal Safety | Genomics Services
Disaggregation of Revenue [Line Items]
Total Revenues	19,596	17,386	38,300	34,901
Animal Safety | Life Sciences
Disaggregation of Revenue [Line Items]
Total Revenues	1,427	1,309	3,016	2,672
Animal Safety | Veterinary Instruments & Disposables
Disaggregation of Revenue [Line Items]
Total Revenues	16,433	15,572	31,106	30,909
Animal Safety | Animal Care & Other
Disaggregation of Revenue [Line Items]
Total Revenues	$ 10,569	$ 10,849	$ 21,095	$ 20,068