FAIR VALUE (Tables)

12 Months Ended

Dec. 31, 2013

Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes our fair value measurements at December 31, 2013 and 2012, respectively, for financial assets measured at fair value on a recurring basis:

			Fair Value Measurements Using
	Fair Value		Quoted Prices in Active Markets (Level 1)		Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	(in millions)
December 31, 2013
Cash equivalents	$	876	$	876	$	0	$	0
Debt securities:
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations		584		0		584		0
Mortgage-backed securities		1,820		0		1,820		0
Tax-exempt municipal securities		2,971		0		2,958		13
Mortgage-backed securities:
Residential		22		0		22		0
Commercial		673		0		673		0
Asset-backed securities		63		0		62		1
Corporate debt securities		3,667		0		3,644		23
Total debt securities		9,800		0		9,763		37
Total invested assets	$	10,676	$	876	$	9,763	$	37
December 31, 2012
Cash equivalents	$	1,177	$	1,177	$	0	$	0
Debt securities:
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations		618		0		618		0
Mortgage-backed securities		1,603		0		1,603		0
Tax-exempt municipal securities		3,071		0		3,058		13
Mortgage-backed securities:
Residential		34		0		34		0
Commercial		659		0		659		0
Asset-backed securities		68		0		67		1
Corporate debt securities		3,794		0		3,770		24
Total debt securities		9,847		0		9,809		38
Total invested assets	$	11,024	$	1,177	$	9,809	$	38

Changes in Fair Value of Assets Measured Using Significant Unobservable Inputs

During the years ended December 31, 2013, 2012, and 2011, the changes in the fair value of the assets measured using significant unobservable inputs (Level 3) were comprised of the following:

	For the years ended December 31,
	2013								2012								2011
	Private Placements			Auction Rate Securities		Total			Private Placements		Auction Rate Securities			Total			Private Placements			Auction Rate Securities			Total
	(in millions)
Beginning balance at January 1	$	25		$	13	$	38		$	25	$	16		$	41		$	14		$	52		$	66
Total gains or losses:
Realized in earnings		0			0		0			0		0			0			1			1			2
Unrealized in other comprehensive income		0			0		0			0		0			0			0			1			1
Purchases		0			0		0			0		0			0			17			0			17
Sales		0			0		0			0		(3	)		(3	)		(7	)		(38	)		(45	)
Settlements		(1	)		0		(1	)		0		0			0			0			0			0
Balance at December 31	$	24		$	13	$	37		$	25	$	13		$	38		$	25		$	16		$	41