v3.26.1
Segment Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
May 31, 2026
May 31, 2025
May 31, 2024
Segment Reporting Information [Line Items]      
Operating Expenses $ 430.1 $ 1,482.4 $ 405.3
Operating Income (Loss) (21.6) (1,061.0) 58.6
Depreciation and Amortization 116.3 119.5 116.7
Interest Expense 57.6 68.5 67.0
Total Assets 3,346.0 3,443.8  
Operating Segments      
Segment Reporting Information [Line Items]      
Total Revenues 899.9 927.0 936.0
Net Revenue 870.4 894.7 924.2
Total Cost of Revenues 461.9 473.3 460.3
Operating Expenses 430.1 1,482.4 405.3
Operating Income (Loss) (21.6) (1,061.0) 58.6
Depreciation and Amortization 116.3 119.5 116.7
Interest Expense 60.4 71.6 73.4
Total Assets 3,346.0 3,443.8 4,548.8
Expenditures for long-lived assets 51.3 104.6 111.4
Operating Segments | Food Safety      
Segment Reporting Information [Line Items]      
Total Revenues 662.6 660.0 658.3
Net Revenue 641.1 638.1 655.3
Total Cost of Revenues 317.1 308.7 301.6
Operating Expenses 260.6 1,315.1 271.3
Operating Income (Loss) 63.4 (985.7) 82.4
Depreciation and Amortization 104.8 105.0 102.3
Interest Expense 0.0 0.0 0.0
Total Assets 2,875.4 2,991.7 4,035.3
Expenditures for long-lived assets 47.8 96.7 93.0
Operating Segments | Animal Safety      
Segment Reporting Information [Line Items]      
Total Revenues 237.3 267.0 277.7
Net Revenue 229.3 256.6 268.9
Total Cost of Revenues 144.8 164.6 158.7
Operating Expenses 60.0 84.7 70.9
Operating Income (Loss) 24.5 7.3 39.3
Depreciation and Amortization 11.5 14.5 14.4
Interest Expense 0.0 0.0 0.0
Total Assets 285.1 323.1 342.6
Expenditures for long-lived assets 3.5 7.9 18.4
Intersegment Revenue      
Segment Reporting Information [Line Items]      
Total Revenues (29.5) (32.3) (11.8)
Intersegment Revenue | Food Safety      
Segment Reporting Information [Line Items]      
Total Revenues (21.5) (21.9) (3.0)
Intersegment Revenue | Animal Safety      
Segment Reporting Information [Line Items]      
Total Revenues (8.0) (10.4) (8.8)
Corporate and Eliminations | Operating Segments      
Segment Reporting Information [Line Items]      
Total Revenues [1] 0.0 0.0 0.0
Net Revenue [1] 0.0 0.0 0.0
Total Cost of Revenues [1] 0.0 0.0 0.0
Operating Expenses [1] 109.5 82.6 63.1
Operating Income (Loss) [1] (109.5) (82.6) (63.1)
Depreciation and Amortization [1] 0.0 0.0 0.0
Interest Expense [1] 60.4 71.6 73.4
Total Assets [1] 185.5 129.0 170.9
Expenditures for long-lived assets [1] 0.0 0.0 0.0
Corporate and Eliminations | Intersegment Revenue      
Segment Reporting Information [Line Items]      
Total Revenues [1] $ 0.0 $ 0.0 $ 0.0
[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.