Consolidated Statement of Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Accumulated Deficit	AOCI Attributable to Parent [Member]	Common Stock Held in Treasury	Total Stockholder's Equity	Noncontrolling Interests
Contributions from noncontrolling interest	$ 0
Balance (in shares) at Dec. 31, 2018		1,579				130
Balance at Dec. 31, 2018	17,892	$ 158	$ 26,013	$ (12,041)	$ (605)	$ (3,727)	$ 9,798	$ 8,094
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards (in shares)		3				1
Exercised and issued stock-based awards	1		1				1
Stock-based compensation, including the tender of shares	16		23			$ (7)	16
Dividends	(143)		(73)				(73)	(70)
Changes in noncontrolling interests	(12)		(1)				(1)	(11)
Net loss attributable to common stockholders	31			31			31
Net income (loss) attributable to noncontrolling interests	45							45
Other comprehensive income	11				11		11	0
Balance (in shares) at Mar. 31, 2019		1,582				131
Balance at Mar. 31, 2019	17,841	$ 158	25,963	(12,010)	(594)	$ (3,734)	9,783	8,058
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total liabilities	23,361
Contributions from noncontrolling interest	32		15				15	17
Balance (in shares) at Dec. 31, 2019		1,582				131
Balance at Dec. 31, 2019	17,448	$ 158	25,830	(12,280)	(676)	$ (3,734)	9,298	8,150
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards (in shares)		1
Exercised and issued stock-based awards	1		1				1
Stock-based compensation, including the tender of shares	24		29			$ (5)	24	0
Net loss attributable to common stockholders	(491)			(491)			(491)
Net income (loss) attributable to noncontrolling interests	(58)							(58)
Other comprehensive income	7				8		8	(1)
Balance (in shares) at Mar. 31, 2020		1,583				131
Balance at Mar. 31, 2020	16,963	$ 158	$ 25,875	$ (12,771)	$ (668)	$ (3,739)	$ 8,855	$ 8,108
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total liabilities	$ 23,256