SHAREHOLDER'S EQUITY - COMMON STOCK REPURCHASE (Details) - USD ($) $ in Millions	12 Months Ended			28 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Aug. 31, 2015	May 01, 2014
Equity, Class of Treasury Stock [Line Items]
Common stock repurchase (in shares)	981,277	2,594,809	7,208,328
Common stock repurchase	$ 75	$ 193	$ 505
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)	981,277	2,594,809	1,517,277	5,093,363
Common stock repurchase	$ 75	$ 193	$ 120	$ 388
2014 Repurchase Program – $650 million
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount						$ 650
Common stock repurchase (in shares)	0	0	5,691,051
Common stock repurchase	$ 0	$ 0	$ 385