CASH, CASH EQUIVALENTS, AND MARKETABLE SECURITIES

12 Months Ended

Dec. 31, 2011

CASH, CASH EQUIVALENTS, AND MARKETABLE SECURITIES

Note 2—CASH, CASH EQUIVALENTS, AND MARKETABLE SECURITIES

As of December 31, 2011 and 2010 our cash, cash equivalents, and marketable securities primarily consisted of cash, U.S. and foreign government and agency securities, AAA-rated money market funds, and other investment grade securities. Such amounts are recorded at fair value. The following table summarizes, by major security type, our assets that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in millions):

	December 31, 2011
	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Total Estimated Fair Value
Cash	$	1,207	$	0	$	0		$	1,207
Level 1 securities:
Money market funds		3,651		0		0			3,651
Equity securities		2		0		(1	)		1
Level 2 securities:
Foreign government and agency securities		1,627		14		(1	)		1,640
U.S. government and agency securities		2,592		3		(2	)		2,593
Corporate debt securities		562		3		(2	)		563
Asset-backed securities		56		0		(1	)		55
Other fixed income securities		22		0		0			22
	$	9,719	$	20	$	(7	)	$	9,732
Less: Long-term restricted cash, cash equivalents, and marketable securities (1)									(156	)
Total cash, cash equivalents, and marketable securities								$	9,576
	December 31, 2010
	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Total Estimated Fair Value
Cash	$	613	$	—	$	—		$	613
Level 1 securities:
Money market funds		1,882		—		—			1,882
Equity securities		2		—		(1	)		1
Level 2 securities:
Foreign government and agency securities		2,152		7		(1	)		2,158
U.S. government and agency securities		3,746		11		(1	)		3,756
Corporate debt securities		457		3		(1	)		459
Asset-backed securities		32		1		—			33
Other fixed income securities		17		—		—			17
	$	8,901	$	22	$	(4	)	$	8,919
Less: Long-term restricted cash, cash equivalents, and marketable securities (1)									(157	)
Total cash, cash equivalents, and marketable securities								$	8,762

(1) We are required to pledge or otherwise restrict a portion of our cash, cash equivalents, and marketable securities as collateral for standby letters of credit, guarantees, debt, and real estate lease agreements. We classify cash and marketable securities with use restrictions of twelve months or longer as non-current “Other assets” on our consolidated balance sheets. See “Note 7—Commitments and Contingencies.”

The following table summarizes gross gains and gross losses realized on sales of available-for-sale marketable securities (in millions):

	Year Ended December 31,
	2011		2010		2009
Realized gains	$	15	$	5	$	4
Realized losses		11		4		—

The following table summarizes contractual maturities of our cash equivalent and marketable fixed-income securities as of December 31, 2011 (in millions):

	Amortized Cost		Estimated Fair Value
Due within one year	$	6,011	$	6,012
Due after one year through five years		2,498		2,512
	$	8,509	$	8,524