Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Quarterly Financial Data [Abstract]
Net sales	$ 4,971	$ 4,684	$ 4,570	$ 4,147	$ 4,888	$ 4,456	$ 4,248	$ 3,816	$ 18,372	$ 17,408	$ 15,264
Gross profit	2,128	2,001	1,925	1,761	2,059	1,942	1,817	1,614	7,815	7,432
Net earnings common stockholders	$ 717	$ 604	$ 520	$ 465	$ 617	$ 712	$ 482	$ 392	$ 2,306	$ 2,203	$ 1,518
Basic earnings per common share	$ 1.17	$ 0.98	$ 0.85	$ 0.74	$ 0.98	$ 1.13	$ 0.76	$ 0.61	$ 3.74	$ 3.48	$ 2.35
Diluted earnings per common share	1.16	0.97	0.84	0.74	0.97	1.12	0.76	0.61	3.71	3.46	2.35
Dividends per common share	$ 0.49	$ 0.49	$ 0.49	$ 0.49	$ 0.485	$ 0.485	$ 0.485	$ 0.485	$ 1.96	$ 1.94	$ 1.92
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)	$ 0	$ (189)	$ 0
Net income tax expense (benefit), tax reform, per diluted share								$ (0.07)		$ (0.30)