Fair Value Measurements and Investments (Tables)

3 Months Ended

Dec. 31, 2023

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, 2023		September 30, 2023		December 31, 2023		September 30, 2023
	(in millions)
Assets
Cash equivalents and restricted cash equivalents:
Money market funds	$	10,316	$	13,504	$	—	$	—
U.S. government-sponsored debt securities	—		—		28		—
U.S. Treasury securities	95		301		—		—
Investment securities:
Marketable equity securities	397		339		—		—
U.S. government-sponsored debt securities	—		—		1,580		1,108
U.S. Treasury securities	5,837		4,316		—		—
Other current and non-current assets:
Money market funds	28		23		—		—
Derivative instruments	—		—		154		293
Total	$	16,673	$	18,483	$	1,762	$	1,401
Liabilities
Accrued compensation and benefits:
Deferred compensation liability	$	221	$	175	$	—	$	—
Accrued and other liabilities:
Derivative instruments	—		—		287		396
Total	$	221	$	175	$	287	$	396

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:

	December 31, 2023
	Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses
	(in millions)
U.S. government-sponsored debt securities	$	1,607	$	2	$	(1)	$	1,608
U.S. Treasury securities	5,956		19		(43)		5,932
Total	$	7,563	$	21	$	(44)	$	7,540

	September 30, 2023
	Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses
	(in millions)
U.S. government-sponsored debt securities	$	1,109	$	1	$	(2)	$	1,108
U.S. Treasury securities	4,697		—		(80)		4,617
Total	$	5,806	$	1	$	(82)	$	5,725

Debt securities with unrealized losses for less than 12 months and 12 months or greater were as follows:

	December 31, 2023
	Less Than 12 Months				12 Months or Greater
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in millions)
U.S. government-sponsored debt securities	$	424	$	(1)	$	—	$	—
U.S. Treasury securities	646		(2)		2,056		(41)
Total	$	1,070	$	(3)	$	2,056	$	(41)

	September 30, 2023
	Less Than 12 Months				12 Months or Greater
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in millions)
U.S. government-sponsored debt securities	$	412	$	(2)	$	50	$	—
U.S. Treasury securities	1,360		(12)		2,128		(68)
Total	$	1,772	$	(14)	$	2,178	$	(68)

Debt Securities Classified by Contractual Maturity Date

The stated maturities of debt securities were as follows:

	December 31, 2023
	(in millions)
Due within one year	$	4,731
Due after one year through five years	2,809
Total	$	7,540

Schedule of Non-Marketable Equity Securities

The following table summarizes the total carrying value of the Company’s non-marketable equity securities that were accounted for using the fair value measurement alternative and held as of December 31, 2023, including the cumulative unrealized gains and losses:

	December 31, 2023
	(in millions)
Initial cost basis	$	710
Adjustments:
Upward adjustments	909
Downward adjustments (including impairment)	(430)
Carrying amount	$	1,189

Unrealized gains and losses included in the carrying value of the Company’s non-marketable equity securities accounted for using the fair value measurement alternative and still held as of December 31, 2023 and 2022, respectively, were as follows:

	Three Months Ended December 31,
	2023		2022
	(in millions)
Upward adjustments	$	9	$	17
Downward adjustments (including impairment)	$	—	$	—