Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2018

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair value hierarchy for assets and liabilities measured at fair value on a recurring basis

The following table presents our fair value hierarchy for assets and liabilities measured at fair value on a recurring basis at September 30, 2018 (in millions):

	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents	$	7,147	$	2,867	$	—	$	10,014
Marketable securities:
Corporate bonds and notes	—		144		—		144
Auction rate securities	—		—		35		35
Equity and preferred securities	167		—		—		167
Total marketable securities	167		144		35		346
Derivative instruments	—		3		—		3
Other investments	380		—		16		396
Total assets measured at fair value	$	7,694	$	3,014	$	51	$	10,759
Liabilities
Derivative instruments	$	—	$	71	$	—	$	71
Other liabilities	380		—		86		466
Total liabilities measured at fair value	$	380	$	71	$	86	$	537

Activity for assets classified within Level 3 of the valuation hierarchy

The following table includes the activity for marketable securities, other investments and other liabilities classified within Level 3 of the valuation hierarchy (in millions):

	2018									2017
	Marketable Securities			Other Investments			Other Liabilities			Marketable Securities			Other Investments			Other Liabilities
Beginning balance of Level 3	$	40		$	125		$	196		$	43		$	37		$	—
Total realized and unrealized gains or losses:
Included in selling, general and administrative and other expenses	—			—			(64		)	—			—			(7		)
Included in investment and other income, net	—			6			—			—			3			—
Included in other comprehensive (loss) income	—			7			—			—			8			—
Issuances	—			—			—			—			—			203
Purchases	—			7			—			—			111			—
Sales	—			—			—			—			—			—
Settlements	(5		)	(129		)	(46		)	(3		)	(34		)	—
Transfers into Level 3	—			—			—			—			—			—
Transfers out of Level 3	—			—			—			—			—			—
Ending balance of Level 3	$	35		$	16		$	86		$	40		$	125		$	196

Activity for liabilities classified within Level 3 of the valuation hierarchy [Table Text Block]

The following table includes the activity for marketable securities, other investments and other liabilities classified within Level 3 of the valuation hierarchy (in millions):

	2018									2017
	Marketable Securities			Other Investments			Other Liabilities			Marketable Securities			Other Investments			Other Liabilities
Beginning balance of Level 3	$	40		$	125		$	196		$	43		$	37		$	—
Total realized and unrealized gains or losses:
Included in selling, general and administrative and other expenses	—			—			(64		)	—			—			(7		)
Included in investment and other income, net	—			6			—			—			3			—
Included in other comprehensive (loss) income	—			7			—			—			8			—
Issuances	—			—			—			—			—			203
Purchases	—			7			—			—			111			—
Sales	—			—			—			—			—			—
Settlements	(5		)	(129		)	(46		)	(3		)	(34		)	—
Transfers into Level 3	—			—			—			—			—			—
Transfers out of Level 3	—			—			—			—			—			—
Ending balance of Level 3	$	35		$	16		$	86		$	40		$	125		$	196