Debt (Tables)

6 Months Ended

Mar. 31, 2017

Debt Disclosure [Abstract]

Schedule of Debt

The Company had outstanding debt as follows:

	March 31, 2017							September 30, 2016
	Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Effective Interest Rate
	(in millions, except percentages)
1.20% Senior Notes due December 2017 (the "2017 Notes")	$	1,750	$	(2	)	$	1,748	$	—	$	—		$	—	1.37	%
Total current maturities of long-term debt	1,750		(2		)	1,748		—		—			—
1.20% Senior Notes due December 2017 (the "2017 Notes")	—		—			—		1,750		(4		)	1,746		1.37	%
2.20% Senior Notes due December 2020 (the "2020 Notes")	3,000		(11		)	2,989		3,000		(12		)	2,988		2.30	%
2.80% Senior Notes due December 2022 (the "2022 Notes")	2,250		(11		)	2,239		2,250		(12		)	2,238		2.89	%
3.15% Senior Notes due December 2025 (the "2025 Notes")	4,000		(34		)	3,966		4,000		(36		)	3,964		3.26	%
4.15% Senior Notes due December 2035 (the "2035 Notes")	1,500		(15		)	1,485		1,500		(15		)	1,485		4.23	%
4.30% Senior Notes due December 2045 (the "2045 Notes")	3,500		(39		)	3,461		3,500		(39		)	3,461		4.37	%
Total long-term debt	14,250		(110		)	14,140		16,000		(118		)	15,882
Total debt	$	16,000	$	(112	)	$	15,888	$	16,000	$	(118	)	$	15,882