STOCK-BASED COMPENSATION - Stock Option Shares Outstanding and Exercisable (Details) shares in Millions	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Stock-based compensation
Exercise price range, low end of range (in dollars per share)	$ 10
Exercise price range, high end of range (in dollars per share)	$ 12
Option Shares Outstanding, Number of shares (in shares) | shares	3
Weighted Average Remaining Option Term	6 years
Option Shares Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 27
Option Shares Exercisable, Number of Shares (in shares) | shares	2
Option Shares Exercisable, Weighted Average Exercise price (in dollars per share)	$ 21
Range One
Stock-based compensation
Exercise price range, low end of range (in dollars per share)	18
Exercise price range, high end of range (in dollars per share)	$ 26
Option Shares Outstanding, Number of shares (in shares) | shares	0
Weighted Average Remaining Option Term	1 year
Option Shares Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11
Option Shares Exercisable, Number of Shares (in shares) | shares	0
Option Shares Exercisable, Weighted Average Exercise price (in dollars per share)	$ 11
Range Two
Stock-based compensation
Exercise price range, low end of range (in dollars per share)	30
Exercise price range, high end of range (in dollars per share)	$ 42
Option Shares Outstanding, Number of shares (in shares) | shares	2
Weighted Average Remaining Option Term	4 years
Option Shares Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 21
Option Shares Exercisable, Number of Shares (in shares) | shares	2
Option Shares Exercisable, Weighted Average Exercise price (in dollars per share)	$ 20
Range Three
Stock-based compensation
Exercise price range, low end of range (in dollars per share)	10
Exercise price range, high end of range (in dollars per share)	$ 42
Option Shares Outstanding, Number of shares (in shares) | shares	1
Weighted Average Remaining Option Term	8 years
Option Shares Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 37
Option Shares Exercisable, Number of Shares (in shares) | shares	0
Option Shares Exercisable, Weighted Average Exercise price (in dollars per share)	$ 36