Marketable Securities And Cash Equivalents (Tables)

9 Months Ended

Sep. 30, 2013

Investments, Debt and Equity Securities [Abstract]

Marketable Securities and Cash Equivalents

	Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(In millions)
September 30, 2013
United States government obligations
Maturity less than 1 year	$	465	$	—	$	—		$	465
Maturity 1 to 5 years	127		—		—			127
Government–sponsored enterprise obligations
Maturity 1 to 5 years	2		—		—			2
Corporate debt securities
Maturity 1 to 5 years	15		—		—			15
Other debt securities
Maturity less than 1 year	2,440		—		—			2,440
Maturity 1 to 5 years	3		—		—			3
Equity securities
Available-for-sale	538		2		(2		)	538
	$	3,590	$	2	$	(2	)	$	3,590

	Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(In millions)
December 31, 2012
United States government obligations
Maturity less than 1 year	$	583	$	—	$	—		$	583
Maturity 1 to 5 years	93		—		—			93
Government–sponsored enterprise obligations
Maturity 1 to 5 years	2		—		—			2
Corporate debt securities
Maturity 1 to 5 years	15		—		—			15
Other debt securities
Maturity less than 1 year	1,038		—		—			1,038
Maturity 1 to 5 years	3		—		—			3
Equity securities
Available-for-sale	606		3		(5		)	604
	$	2,340	$	3	$	(5	)	$	2,338