SHAREHOLDER'S EQUITY - COMMON STOCK REPURCHASE (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2015	May. 01, 2014	Sep. 01, 2012
Equity, Class of Treasury Stock [Line Items]
Common stock repurchase (in shares)	7,208,328	7,316,731	4,984,186
Common stock repurchase	$ 505	$ 348	$ 159
2015 $1 billion Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount				$ 1,000
Common stock repurchase (in shares)	1,517,277
Common stock repurchase	$ 120
2014 $650 million Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount					$ 650
Common stock repurchase (in shares)	5,691,051	5,497,427
Common stock repurchase	$ 385	$ 265
2012 $250 million Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount						$ 250
Common stock repurchase (in shares)	0	1,819,304	4,984,186
Common stock repurchase	$ 0	$ 83	$ 159