Fair Value Measurements and Investments (Tables)

3 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	Fair Value Measurements Using Inputs Considered as
	Level 1				Level 2
	December 31, 2016		September 30, 2016		December 31, 2016		September 30, 2016
	(in millions)
Assets
Cash equivalents and restricted cash:
Money market funds	$	4,819	$	4,537
U.S. government-sponsored debt securities					$	—	$	196
Investment securities, trading:
Equity securities	82		71
Investment securities, available-for-sale:
U.S. government-sponsored debt securities					4,671		4,699
U.S. Treasury securities	2,554		2,178
Equity securities	62		53
Corporate debt securities					130		249
Prepaid and other current assets:
Foreign exchange derivative instruments					88		50
Other assets:
Foreign exchange derivative instruments					2		6
Total	$	7,517	$	6,839	$	4,891	$	5,200
Liabilities
Accrued liabilities:
Foreign exchange derivative instruments					$	76	$	116
Other liabilities:
Foreign exchange derivative instruments					8		20
Total	$	—	$	—	$	84	$	136

Schedule of Long-term Debt Instruments

The following table presents the carrying amount and estimated fair value of the Company’s debt in order of maturity.

	December 31, 2016				September 30, 2016
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
	(in millions)
1.20% Senior Notes due December 2017	$	1,747	$	1,750	$	1,746	$	1,754
2.20% Senior Notes due December 2020	2,988		3,009		2,988		3,077
2.80% Senior Notes due December 2022	2,239		2,263		2,238		2,359
3.15% Senior Notes due December 2025	3,965		4,018		3,964		4,225
4.15% Senior Notes due December 2035	1,485		1,570		1,485		1,698
4.30% Senior Notes due December 2045	3,461		3,694		3,461		4,045
Total	$	15,885	$	16,304	$	15,882	$	17,158