INCOME TAXES - Components of Benefit from Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of loss before benefit of income taxes
Domestic	$ (2,396)	$ (1,475)	$ (2,032)
Foreign	559	(2,679)	291
Loss before benefit from income taxes	(1,837)	(4,154)	(1,741)
Current:
Domestic	(12)	0	(20)
Foreign	(116)	(327)	(146)
Total	(128)	(327)	(166)
Deferred:
Domestic	(5)	17	(2)
Foreign	187	320	4,313
Total	182	337	4,311
(Provision for) benefit from income taxes	$ 54	$ 10	$ 4,145