BUSINESS SEGMENTS - Depreciation & Amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 372	$ 417	$ 1,139	$ 1,263
National Instruments
Segment Reporting Information [Line Items]
Amortization of intangible assets		34		102
Operating Segments \| Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	108	109	324	333
Operating Segments \| Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	253	298	783	898
Operating Segments \| Final Control \| Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	39	41	120	120
Operating Segments \| Measurement & Analytical \| Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	32	32	95	105
Operating Segments \| Discrete Automation \| Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	22	22	64	65
Operating Segments \| Safety & Productivity \| Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	15	14	45	43
Operating Segments \| Control Systems & Software \| Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	134	148	427	444
Operating Segments \| Test & Measurement \| Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	119	150	356	454
Corporate and other
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 11	$ 10	$ 32	$ 32