Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Quarterly Financial Data [Abstract]
Net sales	$ 4,435	$ 4,039	$ 3,574	$ 3,216	$ 3,932	$ 3,674	$ 3,579	$ 3,337	$ 15,264	$ 14,522	$ 16,249
Gross profit	1,804	1,678	1,557	1,365	1,713	1,593	1,542	1,414	6,404	6,262
Earnings from continuing operations common stockholders	496	407	376	364	479	441	367	303	1,643	1,590	2,517
Net earnings common stockholders	$ 504	$ 413	$ 292	$ 309	$ 438	$ 479	$ 369	$ 349	$ 1,518	$ 1,635	$ 2,710
Basic earnings from continuing operations per common share	$ 0.77	$ 0.63	$ 0.58	$ 0.56	$ 0.74	$ 0.68	$ 0.57	$ 0.47	$ 2.54	$ 2.46	$ 3.72
Diluted earnings from continuing operations per common share	0.77	0.63	0.58	0.56	0.74	0.68	0.57	0.46	2.54	2.45	3.71
Basic earnings per common share	0.78	0.64	0.45	0.48	0.68	0.74	0.57	0.54	2.35	2.53	4.01
Diluted earnings per common share	0.78	0.64	0.45	0.48	0.68	0.74	0.57	0.53	2.35	2.52	3.99
Dividends per common share	0.48	0.48	0.48	0.48	0.475	0.475	0.475	0.475	1.92	1.90	$ 1.88
Common stock prices: High	64.18	61.63	64.36	58.28	56.72	56.82	55.54	51.47	64.36	56.82
Common stock prices: Low	$ 57.81	$ 56.77	$ 55.40	$ 49.22	$ 50.41	$ 48.45	$ 41.25	$ 42.21	$ 49.22	$ 41.25