CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Abstract]
Cash	$ 3		$ 4
Money market funds and other securities	75		69
Cash and cash equivalents	78	$ 51	73	$ 107
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	1,478		1,260
Marketable securities, Unrealized Gains	10		1
Marketable securities, Unrealized Losses	(2)		(6)
Marketable securities, Fair Value	1,486		1,255
Cash and marketables securities, Cost Basis	1,556		1,333
Cash and marketable securities, Unrealized Gains	10		1
Cash and marketable securities, Unrealized Losses	(2)		(6)
Total cash and marketable securities	1,564		1,328
Available-for-sale Securities, Activity [Abstract]
Proceeds from sales and maturities	140	259
Gross realized gains	0	1
Gross realized losses	0	$ (1)
U.S. government and agency securities [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	410		254
Marketable securities, Unrealized Gains	2		0
Marketable securities, Unrealized Losses	0		(1)
Marketable securities, Fair Value	412		253
Foreign government bonds [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	28		31
Marketable securities, Unrealized Gains	0		0
Marketable securities, Unrealized Losses	0		0
Marketable securities, Fair Value	28		31
Asset-backed securities [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	154		130
Marketable securities, Unrealized Gains	1		0
Marketable securities, Unrealized Losses	(1)		0
Marketable securities, Fair Value	154		130
Mortgage-backed securities [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	120		117
Marketable securities, Unrealized Gains	1		0
Marketable securities, Unrealized Losses	0		(1)
Marketable securities, Fair Value	121		116
Corporate notes and bonds [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	749		711
Marketable securities, Unrealized Gains	6		1
Marketable securities, Unrealized Losses	(1)		(4)
Marketable securities, Fair Value	754		708
Municipal securities [Member]
Available-for-sale Securities, Current [Abstract]
Marketable securities, Cost Basis	17		17
Marketable securities, Unrealized Gains	0		0
Marketable securities, Unrealized Losses	0		0
Marketable securities, Fair Value	$ 17		$ 17