BUSINESS SEGMENTS - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2026 USD ($) segment	Mar. 31, 2025 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			5
Stock compensation	$ 4	$ 9	$ 9	$ 11
Acquisition/divestiture fees and related costs	1	144	2	157
National Instruments
Segment Reporting Information [Line Items]
Acquisition/divestiture fees and related costs	$ 7	$ 160	14	179
Restructuring Charges
Segment Reporting Information [Line Items]
Stock compensation			$ 1	$ 1

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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