Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Quarterly Financial Data [Abstract]
Net sales	$ 4,888	$ 4,456	$ 4,248	$ 3,816	$ 4,435	$ 4,039	$ 3,574	$ 3,216	$ 17,408	$ 15,264	$ 14,522
Gross profit	2,065	1,949	1,825	1,621	1,804	1,678	1,557	1,365	7,460	6,404
Earnings from continuing operations common stockholders	617	712	482	392	496	407	376	364	2,203	1,643	1,590
Net earnings common stockholders	$ 617	$ 712	$ 482	$ 392	$ 504	$ 413	$ 292	$ 309	$ 2,203	$ 1,518	$ 1,635
Basic earnings from continuing operations per common share	$ 0.98	$ 1.13	$ 0.76	$ 0.61	$ 0.77	$ 0.63	$ 0.58	$ 0.56	$ 3.48	$ 2.54	$ 2.46
Diluted earnings from continuing operations per common share	0.97	1.12	0.76	0.61	0.77	0.63	0.58	0.56	3.46	2.54	2.45
Basic earnings per common share	0.98	1.13	0.76	0.61	0.78	0.64	0.45	0.48	3.48	2.35	2.53
Diluted earnings per common share	0.97	1.12	0.76	0.61	0.78	0.64	0.45	0.48	3.46	2.35	2.52
Dividends per common share	$ 0.485	$ 0.485	$ 0.485	$ 0.485	$ 0.48	$ 0.48	$ 0.48	$ 0.48	$ 1.94	$ 1.92	$ 1.90
Income tax expense (benefit) due to increase in foreign tax credit carryforwards		$ (150)
Income tax expense (benefit) due to increase in foreign tax credit carryforwards, per diluted share		$ (0.24)
Net income tax expense (benefit), tax reform				$ (43)					$ (189)	$ 0	$ 0
Net income tax expense (benefit), tax reform, per diluted share				$ (0.07)					$ (0.30)