GUARANTOR FINANCIAL STATEMENTS (Condensed Consolidating Comprehensive (Loss) Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues	$ 14,198	$ 14,402	$ 18,628
Costs and Expenses	11,761	13,311	13,874
Operating income (loss)	2,437	1,091	4,754
Interest expense, net	(598)	(620)	(945)
Other income (expense), net	59	(138)	76
Net (loss) gain on early extinguishment of debt	(101)	(27)	7
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	1,797	306	3,892
Benefit from (provision for) income taxes	(944)	(510)	(991)
Equity in affiliated companies’ net earnings (losses)	12	12	8
Net income (loss) from continuing operations	865	(192)	2,909
Net income (loss) from discontinued operations	0	3	(15)
Net income (loss)	865	(189)	2,894
Net (loss) income attributable to common stockholders	599	(239)	2,602
Total comprehensive income (loss) attributable to common stockholders	$ 692	$ (310)	$ 2,569