STOCKHOLDERS' EQUITY AND STOCK-BASED COMPENSATION STOCKHOLDERS' EQUITY AND STOCK-BASED COMPENSATION (Stock Option and SARs) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance at beginning of period (in number of options/units)	48,014,688
Granted (in number of options/units)	3,315,000
Exercised (in number of options/units)	(801,706)
Expired/Forfeited (in number of options/units)	(3,721,618)
Balance at end of period (in number of options/units)	46,806,364	48,014,688
Weighted-average exercise price at beginning of period (in dollars per option)	$ 28.63
Granted, Exercise Price (in dollars per option)	18.74
Exercised, Exercise Price (in dollars per option)	10.05
Expired/Forfeited, Exercise Price (in dollars per option)	39.26
Weighted-average exercise price at end of period (in dollars per option)	$ 27.40	$ 28.63
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 38
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	39,919,885
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 29.80
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 26
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Annual vesting percentage	33.00%	25.00%
Total unrecognized compensation cost related to unvested options expected to be recognized over a weighted-average period	$ 23
Weighted-average period used in calculating unrecognized compensation cost, stock options (in years)	1 year 5 months
Fair value assumptions and methodology [Abstract]
Weighted-average expected volatility	46.10%	51.40%	71.60%
Expected life of options (in years)	5 years 11 months	5 years 8 months 11 days	5 years 4 months 3 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	1.20%	0.00%	0.00%
Risk free interest rate	2.60%	2.00%	1.30%
Weighted-average grant-date fair value (in dollars per option)	$ 7.84	$ 7.61	$ 2.64
Total intrinsic value of options exercised	$ 7	$ 5	$ 0
Fair value of options vested	$ 24	$ 25	$ 43
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage		33.00%