Supplementary Data (Unaudited) Supplementary Data (Unaudited) - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 3,231	$ 3,198	$ 3,067	$ 2,986	$ 3,059	$ 3,120	$ 2,051	$ 2,051	$ 12,483	$ 10,282	$ 8,446
Gross Profit	1,552	1,547	1,484	1,408	1,430	1,174	1,046	1,045	5,991	4,695
Net Income	$ 19	$ 390	$ 338	$ 229	$ 181	$ 62	$ 216	$ 236	$ 976	$ 695	$ 1,185
Earnings per Share:
Basic Earnings per Share (USD per share)	$ 0.09	$ 1.83	$ 1.59	$ 1.08	$ 0.86	$ 0.30	$ 1.10	$ 1.22	$ 4.59	$ 3.43	$ 6.13
Diluted Earnings per Share (USD per share)	$ 0.09	$ 1.80	$ 1.56	$ 1.06	$ 0.84	$ 0.29	$ 1.08	$ 1.20	$ 4.49	$ 3.35	$ 5.99