Fair Value Measurements and Investments (Tables)

3 Months Ended

Dec. 31, 2020

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, 2020		September 30, 2020		December 31, 2020		September 30, 2020
	(in millions)
Assets
Cash equivalents and restricted cash equivalents:
Money market funds	$	10,512	$	12,522	$	—	$	—
U.S. government-sponsored debt securities	—		—		850		1,469
U.S. Treasury securities	2,050		650		—		—
Investment securities:
Marketable equity securities	184		148		—		—
U.S. government-sponsored debt securities	—		—		1,684		2,582
U.S. Treasury securities	1,302		1,253		—		—
Other current and non-current assets:
Money market funds	2		—		—		—
Derivative instruments	—		—		381		512
Total	$	14,050	$	14,573	$	2,915	$	4,563
Liabilities
Accrued compensation and benefits:
Deferred compensation liability	$	169	$	135	$	—	$	—
Accrued and other liabilities:
Derivative instruments	—		—		355		181
Total	$	169	$	135	$	355	$	181

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 December 31, 2020 including cumulative unrealized gains and losses:

	December 31, 2020
	(in millions)
Initial cost basis	$	849
Adjustments:
Upward adjustments	226
Downward adjustments (including impairment)	(13)
Carrying amount, end of period	$	1,062