Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common stockholders' equity	Common stock	Additional paid-in-capital	Additional paid-in-capital AspenTech	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock	Noncontrolling interests in subsidiaries	Noncontrolling interests in subsidiaries AspenTech
Stockholders' equity, beginning balance at Sep. 30, 2021				$ 522		$ 26,047	$ (872)	$ (16,291)	$ 40
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plans				85
AspenTech purchases of common stock					$ 0
Treasury stock, purchases								(500)		$ 0
AspenTech acquisition					(550)					5,890
Purchase of noncontrolling interests									0
Net earnings common stockholders	$ 3,231					3,231
Dividends paid						(1,225)			(4)
Foreign currency translation	(644)						(636)
Pension and postretirement	37						37
Cash flow hedges	(14)						(14)
Issued under Emerson stock plans								53
Net earnings									(1)
Stock plans	(144)								35
Other comprehensive income	(621)								(8)
Climate Technologies divestiture									0
Stockholders' equity, ending balance at Sep. 30, 2022	16,316	$ 10,364	$ 477	57		28,053	(1,485)	(16,738)	5,952
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plans				127
AspenTech purchases of common stock					(122)
Treasury stock, purchases								(2,000)		(92)
AspenTech acquisition					0					0
Purchase of noncontrolling interests									3
Net earnings common stockholders	13,219					13,219
Dividends paid						(1,202)			(1)
Foreign currency translation	254						253
Pension and postretirement	(25)						(25)
Cash flow hedges	4						4
Issued under Emerson stock plans								71
Net earnings									(19)
Stock plans	(271)								94
Other comprehensive income	233								1
Climate Technologies divestiture									(29)
Stockholders' equity, ending balance at Sep. 30, 2023	26,598	20,689	477	62		40,070	(1,253)	(18,667)	5,909
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plans				226
AspenTech purchases of common stock					(119)
Treasury stock, purchases								(435)		(89)
AspenTech acquisition					$ 0					$ 0
Purchase of noncontrolling interests									0
Net earnings common stockholders	1,968					1,968
Dividends paid						(1,208)			(2)
Foreign currency translation	400						396
Pension and postretirement	2						2
Cash flow hedges	(13)						(13)
Issued under Emerson stock plans								130
Net earnings									(13)
Stock plans	(260)								64
Other comprehensive income	389								4
Climate Technologies divestiture									0
Stockholders' equity, ending balance at Sep. 30, 2024	$ 27,509	$ 21,636	$ 477	$ 169		$ 40,830	$ (868)	$ (18,972)	$ 5,873