BUSINESS SEGMENTS - Reconciliation of Net Contribution to Earnings to Net Earnings (Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation From Segment Totals To Consolidated [Abstract]
Net contribution to earnings									$ 165	$ 1,182	$ 1,109
Interest expense, net of capitalized interest									(378)	(375)	(393)
Income (loss) before income taxes									(213)	807	716
Income taxes (Note 21)									137	(59)	(134)
Net earnings (loss)	$ (14)	$ 99	$ 128	$ (289)	$ (93)	$ 255	$ 317	$ 269	$ (76)	$ 748	$ 582