Short-Term And Long-Term Investments And Restricted Deposits (Tables)

Short term and long term investments and restricted deposits by investment type consist of the following ($ in millions):



	December 31, 2014									December 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	393	$	1	$	(2	)	$	392	$	246	$	—	$	(7	)	$	239
Corporate securities	556		2		(2		)	556		294		3		(1		)	296
Restricted certificates of deposit	6		—		—			6		6		—		—			6
Restricted cash equivalents	79		—		—			79		27		—		—			27
Municipal securities:
General obligation	54		—		—			54		54		—		—			54
Pre-refunded	5		—		—			5		11		—		—			11
Revenue	101		1		—			102		69		—		—			69
Variable rate demand notes	14		—		—			14		29		—		—			29
Asset backed securities	180		—		—			180		139		—		—			139
Mortgage backed securities	84		1		—			85		34		—		—			34
Cost and equity method investments	68		—		—			68		22		—		—			22
Life insurance contracts	16		—		—			16		15		—		—			15
Total	$	1,556	$	5	$	(4	)	$	1,557	$	946	$	3	$	(8	)	$	941

The fair value of available-for-sale investments with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows ($ in millions):



	December 31, 2014										December 31, 2013
	Less Than 12 Months					12 Months or More					Less Than 12 Months					12 Months or More
	Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	—		$	72	$	(2	)	$	180	$	(7	)	$	172	$	(1	)	$	27
Corporate securities	(2		)	311		—			1		—			53		—			5
Municipal securities:
General obligation	—			4		—			3		—			4		—			2
Revenue	—			16		—			3		—			28		—			—
Pre-refunded	—			—		—			1		—			—		—			—
Asset backed securities	—			70		—			10		—			38		—			—
Mortgage backed securities	—			18		—			—		—			34		—			—
Total	$	(2	)	$	491	$	(2	)	$	198	$	(7	)	$	329	$	(1	)	$	34

The contractual maturities of short term and long term investments and restricted deposits are as follows ($ in millions):



	December 31, 2014								December 31, 2013
	Investments				Restricted Deposits				Investments				Restricted Deposits
	Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value
One year or less	$	176	$	177	$	92	$	92	$	102	$	102	$	41	$	41
One year through five years	1,121		1,121		8		8		610		611		6		6
Five years through ten years	121		120		—		—		157		151		—		—
Greater than ten years	38		39		—		—		30		30		—		—
Total	$	1,456	$	1,457	$	100	$	100	$	899	$	894	$	47	$	47