Fair Value Measurements and Investments (Tables)

12 Months Ended

Sep. 30, 2020

Fair Value Disclosures [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
	2020		2019		2020		2019
	(in millions)
Assets
Cash equivalents and restricted cash equivalents:
Money market funds	$	12,522	$	6,494	$	—	$	—
U.S. government-sponsored debt securities	—		—		1,469		150
U.S. Treasury securities	650		—		—		—
Investment securities:
Marketable equity securities	148		126		—		—
U.S. government-sponsored debt securities	—		—		2,582		5,592
U.S. Treasury securities	1,253		675		—		—
Other current and non-current assets:
Derivative instruments	—		—		512		437
Total	$	14,573	$	7,295	$	4,563	$	6,179
Liabilities
Accrued compensation and benefits:
Deferred compensation liability	$	135	$	113	$	—	$	—
Accrued and other liabilities:
Derivative instruments	—		—		181		52
Total	$	135	$	113	$	181	$	52

Schedule of Amortized Cost, Unrealized Gains and Losses, and Fair Value of Debt Securities

The amortized cost, unrealized gains and losses and fair value of debt securities were as follows:

	September 30,
	2020								2019
	Amortized Cost		Gross Unrealized				Fair Value		Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses						Gains		Losses
	(in millions)
U.S. government-sponsored debt securities	$	2,581	$	1	$	—	$	2,582	$	5,590	$	4	$	(2)	$	5,592
U.S. Treasury securities	1,251		2		—		1,253		672		3		—		675
Total	$	3,832	$	3	$	—	$	3,835	$	6,262	$	7	$	(2)	$	6,267
Less: current portion							$	(3,604)							$	(4,110)
Long-term debt securities							$	231							$	2,157

Debt Security Investments Classified by Contractual Maturity Date

Debt securities are presented below in accordance with their stated maturities. A portion of these investments are classified as non-current as they have stated maturities of more than one year from the balance sheet date. However, these investments are generally available to meet short-term liquidity needs.

	September 30, 2020
	(in millions)
Due within one year	$	3,604
Due after 1 year through 5 years	231
Total	$	3,835

Schedule of Non-marketable Equity Securities

The following table summarizes the total carrying value of the Company’s non-marketable equity securities held as of September 30, 2020 including cumulative unrealized gains and losses:

	September 30, 2020
	(in millions)
Initial cost basis	$	841
Adjustments:
Upward adjustments	212
Downward adjustments (including impairment)	(11)
Carrying amount, end of period	$	1,042

Investment Income

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

	For the Years Ended September 30,
	2020		2019		2018
	(in millions)
Interest and dividend income on cash and investments	$	80	$	247	$	173
Realized gains (losses), net on debt securities	4		1		—
Equity securities:
Unrealized gains (losses), net	115		117		2
Realized gains (losses), net from donation	—		—		193
Realized gains (losses), net	1		18		102
Investment income	$	200	$	383	$	470