Fair Value Measurements and Investments (Tables)

12 Months Ended

Sep. 30, 2016

Fair Value Measurements and Investments [Abstract]

Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	Fair Value Measurements at September 30 Using Inputs Considered as
	Level 1				Level 2				Level 3
	2016		2015		2016		2015		2016		2015
	(in millions)
Assets
Cash equivalents and restricted cash:
Money market funds	$	4,537	$	3,051
U.S. government-sponsored debt securities					$	196	$	280
Investment securities, trading:
Equity securities	71		66
Investment securities, available-for-sale:
U.S. government-sponsored debt securities					4,699		2,615
U.S. Treasury securities	2,178		2,656
Equity securities	53		4
Corporate debt securities					249		533
Auction rate securities									$	—	$	7
Prepaid and other current assets:
Foreign exchange derivative instruments					50		76
Other Assets:
Foreign exchange derivative instruments					6
Total	$	6,839	$	5,777	$	5,200	$	3,504	$	—	$	7
Liabilities
Accrued liabilities:
Visa Europe put option									$	—	$	255
Foreign exchange derivative instruments					$	116	$	13
Other liabilities:
Foreign exchange derivative instruments					$	20
Total	$	—	$	—	$	136	$	13	$	—	$	255

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

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

	September 30, 2016
	Carrying Amount		Estimated Fair Value
	(in millions)
1.20% Senior Notes due December 2017	$	1,746	$	1,754
2.20% Senior Notes due December 2020	2,988		3,077
2.80% Senior Notes due December 2022	2,238		2,359
3.15% Senior Notes due December 2025	3,964		4,225
4.15% Senior Notes due December 2035	1,485		1,698
4.30% Senior Notes due December 2045	3,461		4,045
	$	15,882	$	17,158

Available-for-sale Securities

The amortized cost, unrealized gains and losses and fair value of available-for-sale investment securities are as follows:

	September 30, 2016									September 30, 2015
	Amortized Cost		Gross Unrealized				Fair Value			Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses							Gains		Losses
	(in millions)
U.S. government-sponsored debt securities	$	4,693	$	6	$	—	$	4,699		$	2,612	$	3	$	—	$	2,615
U.S. Treasury securities	2,176		3		—		2,179			2,652		4		—		2,656
Equity securities	7		46		—		53			4		—		—		4
Corporate debt securities	248		—		—		248			533		—		—		533
Auction rate securities	—		—		—		—			7		—		—		7
Total	$	7,124	$	55	$	—	$	7,179		$	5,808	$	7	$	—	$	5,815
Less: current portion of available-for-sale investment securities							(3,248		)							(2,431		)
Long-term available-for-sale investment securities							$	3,931								$	3,384

Available for Sale Investments Classified by Contractual Maturity Date

	Amortized Cost		Fair Value
	(in millions)
September 30, 2016:
Due within one year	$	3,193	$	3,195
Due after 1 year through 5 years	3,925		3,931
Due after 5 years through 10 years	—		—
Due after 10 years	—		—
Total	$	7,118	$	7,126

Investment Income

Investment income is recorded as non-operating income in the Company's consolidated statements of operations and consisted of the following:

	For the Years Ended September 30,
	2016			2015			2014
	(in millions)
Interest and dividend income on cash and investments	$	75		$	31		$	25
Gain on other investments	5			3			8
Investment securities, trading:
Unrealized gains (losses), net	3			(6		)	(2		)
Realized gains, net	—			2			6
Investment securities, available-for-sale:
Realized gains, net	3			21			1
Other-than-temporary impairment on investments	(4		)	(5		)	(3		)
Investment income	$	82		$	46		$	35