Business Segments - Depreciation & Amortization (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 422	$ 260
National Instruments
Segment Reporting Information [Line Items]
Amortization of intangible assets	139	105
Operating Segments | Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	116	110
Operating Segments | Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	295	144
Operating Segments | Final Control | Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	40	45
Operating Segments | Measurement & Analytical | Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	40	30
Operating Segments | Discrete Automation | Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	22	21
Operating Segments | Safety & Productivity | Intelligent Devices
Segment Reporting Information [Line Items]
Depreciation and amortization	14	14
Operating Segments | Control Systems & Software | Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	21	21
Operating Segments | Test & Measurement | Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	151	0
Operating Segments | AspenTech | Software and Control
Segment Reporting Information [Line Items]
Depreciation and amortization	123	123
Corporate and other
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 11	$ 6