Business Segment Information - Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting [Line Items]
Total revenues	$ 5,935.9	$ 5,459.5	$ 5,138.7
IRELAND
Segment Reporting [Line Items]
Total revenues	108.5	107.3	82.7
UNITED STATES
Segment Reporting [Line Items]
Total revenues	4,333.8	4,007.6	3,751.4
Other foreign locations
Segment Reporting [Line Items]
Total revenues	1,493.7	1,344.6	1,304.6
Healthcare Segment
Segment Reporting [Line Items]
Total revenues	4,208.6	3,878.7	3,613.0
AST
Segment Reporting [Line Items]
Total revenues	1,138.5	1,038.6	954.0
Life Sciences
Segment Reporting [Line Items]
Total revenues	588.8	542.3	571.7
Capital equipment \| Healthcare Segment
Segment Reporting [Line Items]
Total revenues	1,095.9	1,037.2	1,091.5
Capital equipment \| AST
Segment Reporting [Line Items]
Total revenues	20.0	30.9	14.5
Capital equipment \| Life Sciences
Segment Reporting [Line Items]
Total revenues	135.7	117.5	155.5
Consumables \| Healthcare Segment
Segment Reporting [Line Items]
Total revenues	1,496.6	1,396.0	1,248.4
Consumables \| Life Sciences
Segment Reporting [Line Items]
Total revenues	308.3	286.7	251.6
Service \| Healthcare Segment
Segment Reporting [Line Items]
Total revenues	1,616.0	1,445.4	1,273.1
Service \| AST
Segment Reporting [Line Items]
Total revenues	1,118.5	1,007.6	939.5
Service \| Life Sciences
Segment Reporting [Line Items]
Total revenues	$ 144.8	$ 138.1	$ 164.6