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, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance at beginning of period (in number of options/units)	46,806,364
Granted (in number of options/units)	6,425,500
Exercised (in number of options/units)	(391,075)
Expired/Forfeited (in number of options/units)	(4,528,736)
Balance at end of period (in number of options/units)	48,312,053	46,806,364
Weighted-average exercise price at beginning of period (in dollars per option)	$ 27.40
Granted, Exercise Price (in dollars per option)	11.88
Exercised, Exercise Price (in dollars per option)	4.72
Expired/Forfeited, Exercise Price (in dollars per option)	20.55
Weighted-average exercise price at end of period (in dollars per option)	$ 26.16	$ 27.40
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years 4 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 60
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	39,981,705
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 28.86
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 51
Share-based Payment Arrangement, 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 7 months 6 days
Fair value assumptions and methodology [Abstract]
Weighted-average expected volatility	47.80%	46.10%	51.40%
Expected life of options (in years)	6 years 1 month 6 days	5 years 11 months 1 day	5 years 8 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	1.80%	1.20%	0.00%
Risk free interest rate	2.50%	2.60%	2.00%
Weighted-average grant-date fair value (in dollars per option)	$ 4.87	$ 7.84	$ 7.61
Total intrinsic value of options exercised	$ 3	$ 7	$ 5
Fair value of options vested	$ 26	$ 24	$ 25