CAPITAL STOCK - Net Income (loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic:
Loss attributable to common stock	$ (4)	$ (170)	$ (4,870)	$ (577)
Weighted average number of shares outstanding, basic (in shares)	378	377	378	377
Basic net income (loss) per share (in USD per share)	$ (0.01)	$ (0.45)	$ (12.89)	$ (1.53)
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners			$ 0	$ 0
Stock options and other (in shares)			0	0
Stock options and other (in USD per share)			$ 0	$ 0
Diluted:
Loss attributable to common stock	$ (8)	$ (170)	$ (4,870)	$ (577)
Loss attributable to common stock, shares	378	377	378	377
Diluted net income (loss) per share (in USD per share)	$ (0.02)	$ (0.45)	$ (12.89)	$ (1.53)
Altus Preferred Unit limited partners
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	$ (4)	$ 0
Stock options and other (in shares)	0	0
Stock options and other (in USD per share)	$ (0.01)	$ 0
Stock Options and Other
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	$ 0	$ 0
Stock options and other (in shares)	0	0
Stock options and other (in USD per share)	$ 0	$ 0