Fair Value of Financial Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Composition of Investments

The following tables summarize the composition of our short- and long-term investments at December 31, 2015 and 2014 (tables in millions):

	December 31, 2015
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Aggregate Fair Value
U.S. government and agency obligations	$	2,449	$	—	$	(8	)	$	2,441
U.S. corporate debt securities	2,257		1		(10		)	2,248
High yield corporate debt securities	307		2		(22		)	287
Asset-backed securities	20		—		—			20
Municipal obligations	731		1		—			732
Auction rate securities	27		—		(2		)	25
Foreign debt securities	2,332		—		(9		)	2,323
Total fixed income securities	8,123		4		(51		)	8,076
Publicly traded equity securities	126		40		(8		)	158
Total	$	8,249	$	44	$	(59	)	$	8,234

	December 31, 2014
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Aggregate Fair Value
U.S. government and agency obligations	$	1,951	$	2	$	(2	)	$	1,951
U.S. corporate debt securities	1,998		1		(4		)	1,995
High yield corporate debt securities	570		9		(16		)	563
Asset-backed securities	53		—		—			53
Municipal obligations	948		2		—			950
Auction rate securities	29		—		(2		)	27
Foreign debt securities	2,566		2		(4		)	2,564
Total fixed income securities	8,115		16		(28		)	8,103
Publicly traded equity securities	117		103		(11		)	209
Total	$	8,232	$	119	$	(39	)	$	8,312

Fair Value Hierarchy For Financial Assets and Liabilities Measured at Fair Value

The following tables represent our fair value hierarchy for our financial assets and liabilities measured at fair value as of December 31, 2015 and 2014 (tables in millions):

	December 31, 2015
	Level 1		Level 2			Level 3		Total
Cash	$	2,095	$	—		$	—	$	2,095
Cash equivalents	3,861		593			—		4,454
U.S. government and agency obligations	1,495		946			—		2,441
U.S. corporate debt securities	—		2,248			—		2,248
High yield corporate debt securities	—		287			—		287
Asset-backed securities	—		20			—		20
Municipal obligations	—		732			—		732
Auction rate securities	—		—			25		25
Foreign debt securities	—		2,323			—		2,323
Publicly traded equity securities	158		—			—		158
Total cash and investments	$	7,609	$	7,149		$	25	$	14,783
Other items:
Strategic investments carried at cost	$	—	$	—		$	384	$	384
Investment in joint venture	—		—			39		39
Long-term debt carried at discounted issuance cost	—		(4,999		)	—		(4,999		)
Foreign exchange derivative assets	—		39			—		39
Foreign exchange derivative liabilities	—		(78		)	—		(78		)
Commodity derivative liabilities	—		(4		)	—		(4		)

	December 31, 2014
	Level 1		Level 2			Level 3		Total
Cash	$	2,022	$	—		$	—	$	2,022
Cash equivalents	3,710		611			—		4,321
U.S. government and agency obligations	1,141		810			—		1,951
U.S. corporate debt securities	—		1,995			—		1,995
High yield corporate debt securities	—		563			—		563
Asset-backed securities	—		53			—		53
Municipal obligations	—		950			—		950
Auction rate securities	—		—			27		27
Foreign debt securities	—		2,564			—		2,564
Publicly traded equity securities	209		—			—		209
Total cash and investments	$	7,082	$	7,546		$	27	$	14,655
Other items:
Strategic investments carried at cost	$	—	$	—		$	333	$	333
Investment in joint venture	—		—			37		37
Long-term debt carried at discounted issuance cost	—		(5,544		)	—		(5,544		)
Foreign exchange derivative assets	—		44			—		44
Foreign exchange derivative liabilities	—		(71		)	—		(71		)
Commodity derivative assets	—		12			—		12

Unrealized Losses on Investments by Investment Category and Length of Time in Continuous Unrealized Loss Position

Unrealized losses on investments at December 31, 2015 and 2014 by investment category and length of time the investment has been in a continuous unrealized loss position are as follows (tables in millions):

December 31, 2015	Less Than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency obligations	$	1,921	$	(8	)	$	—	$	—		$	1,921	$	(8	)
U.S. corporate debt securities	1,818		(10		)	—		—			1,818		(10		)
High yield corporate debt securities	181		(14		)	33		(8		)	214		(22		)
Asset-backed securities	—		—			—		—			—		—
Auction rate securities	—		—			25		(2		)	25		(2		)
Foreign debt securities	1,753		(8		)	86		(1		)	1,839		(9		)
Publicly traded equity securities	3		—			2		(8		)	5		(8		)
Total	$	5,676	$	(40	)	$	146	$	(19	)	$	5,822	$	(59	)

December 31, 2014	Less Than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency obligations	$	1,168	$	(2	)	$	—	$	—		$	1,168	$	(2	)
U.S. corporate debt securities	1,383		(4		)	—		—			1,383		(4		)
High yield corporate debt securities	244		(16		)	—		—			244		(16		)
Auction rate securities	—		—			27		(2		)	27		(2		)
Foreign debt securities	1,563		(4		)	—		—			1,563		(4		)
Publicly traded equity securities	17		(9		)	3		(2		)	20		(11		)
Total	$	4,375	$	(35	)	$	30	$	(4	)	$	4,405	$	(39	)

Contractual Maturities of Investments

The contractual maturities of fixed income securities held at December 31, 2015 are as follows (table in millions):

	December 31, 2015
	Amortized Cost Basis		Aggregate Fair Value
Due within one year	$	2,722	$	2,721
Due after 1 year through 5 years	4,726		4,704
Due after 5 years through 10 years	413		393
Due after 10 years	262		258
Total	$	8,123	$	8,076