CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES

Components for cash, cash equivalents and marketable securities (in millions):



September 30, 2014	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash	$	5	$	—	$	—		$	5
Cash equivalents	29		—		—			29
Cash and cash equivalents	34		—		—			34
U.S. government and agency securities	204		—		(1		)	203
Foreign government bonds	21		—		—			21
Asset-backed securities	166		—		—			166
Mortgage-backed securities	149		1		(1		)	149
Corporate notes and bonds	747		3		(1		)	749
Municipal securities	21		—		—			21
Marketable securities	1,308		4		(3		)	1,309
Total	$	1,342	$	4	$	(3	)	$	1,343



December 31, 2013	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash	$	9	$	—	$	—		$	9
Cash equivalents	71		—		—			71
Cash and cash equivalents	80		—		—			80
U.S. government and agency securities	295		1		(2		)	294
Foreign government bonds	11		—		—			11
Asset-backed securities	146		—		—			146
Mortgage-backed securities	144		1		(2		)	143
Corporate notes and bonds	628		4		(2		)	630
Municipal securities	26		—		—			26
Marketable securities	1,250		6		(6		)	1,250
Total	$	1,330	$	6	$	(6	)	$	1,330

Unrealized losses from fixed-income securities are primarily attributable to changes in interest rates. Management does not believe any remaining unrealized losses represent other-than-temporary impairments based on our evaluation of available evidence as of September 30, 2014.

Activity for marketable securities (in millions):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014			2013
Proceeds from sales and maturities	$	341	$	247	$	739		$	712
Gross realized gains	1		—		3			3
Gross realized losses	—		—		(1		)	(1		)

Maturities for marketable securities (in millions):



September 30, 2014	Cost Basis		Fair Value
Due in one year or less	$	178	$	178
Due after one year through five years	1,121		1,122
Due after five years through 10 years	8		8
Due after 10 years	1		1
Total	$	1,308	$	1,309