Consolidated Statement of Equity Statement - USD ($) $ in Millions	Total	Common stock	Additional paid-in-capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock	Noncontrolling interests in subsidiaries
Beginning balance at Sep. 30, 2018			$ 348	$ 23,072	$ (1,015)	$ (13,935)	$ 43
Statement [Roll Forward]
Stock plans			32
Net earnings common stockholders	$ 985			985
Dividends paid				(607)			(5)
Foreign currency translation	53				52
Pension and postretirement					25
Cash flow hedges	10				10
Purchases						(1,000)
Issued under stock plans						57
Net earnings							7
Other comprehensive income	88						1
Ending balance at Mar. 31, 2019	8,572	$ 477	380	23,475	(928)	(14,878)	46
Beginning balance at Dec. 31, 2018			375	23,252	(1,052)	(14,816)	40
Statement [Roll Forward]
Stock plans			5
Net earnings common stockholders	520			520
Dividends paid				(302)			0
Foreign currency translation	88				87
Pension and postretirement					12
Cash flow hedges	25				25
Purchases						(75)
Issued under stock plans						13
Net earnings							5
Other comprehensive income	125						1
Ending balance at Mar. 31, 2019	8,572	477	380	23,475	(928)	(14,878)	46
Statement [Roll Forward]
Common stockholders' equity	8,526
Common stockholders' equity	8,233
Beginning balance at Sep. 30, 2019	8,273		393	24,199	(1,722)	(15,114)	40
Statement [Roll Forward]
Stock plans			60
Net earnings common stockholders	843			843
Dividends paid				(611)			(5)
Foreign currency translation	(182)				(183)
Pension and postretirement					58
Cash flow hedges	(56)				(56)
Purchases						(942)
Issued under stock plans						115
Net earnings							10
Other comprehensive income	(180)						1
Ending balance at Mar. 31, 2020	7,563	477	453	24,431	(1,903)	(15,941)	46
Beginning balance at Dec. 31, 2019			447	24,220	(1,576)	(15,147)	38
Statement [Roll Forward]
Stock plans			6
Net earnings common stockholders	517			517
Dividends paid				(306)			0
Foreign currency translation	(281)				(282)
Pension and postretirement					30
Cash flow hedges	(75)				(75)
Purchases						(813)
Issued under stock plans						19
Net earnings							7
Other comprehensive income	(326)						1
Ending balance at Mar. 31, 2020	7,563	$ 477	$ 453	$ 24,431	$ (1,903)	$ (15,941)	$ 46
Statement [Roll Forward]
Common stockholders' equity	$ 7,517