Earnings (Loss) Per 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
Numerator for loss per share, basic
Net income (loss) attributable to controlling interest	$ 359	$ (825)	$ (530)	$ (1,204)
Net loss attributable to controlling interest	$ 359	$ (825)	$ (530)	$ (1,204)
Denominator for loss per share, basic
Weighted-average shares outstanding	615.0	612.0	614.0	611.0
Effect of share-based awards, basic	1.0	1.0	1.0	1.0
Weighted-average shares for per share calculation, basic	616.0	613.0	615.0	612.0
Loss per share, basic (in dollars per share)	$ 0.58	$ (1.35)	$ (0.86)	$ (1.97)
Numerator for loss per share, diluted
Net income (loss) attributable to controlling interest	$ 359	$ (825)	$ (530)	$ (1,204)
Effect of interest expense on convertible debt instruments	1
Net loss attributable to controlling interest	$ 360	$ (825)	$ (530)	$ (1,204)
Denominator for loss per share, diluted
Weighted-average shares outstanding	615.0	612.0	614.0	611.0
Effect of share-based awards, diluted	3.0	1.0	1.0	1.0
Effect of convertible debt instruments, diluted	84.0
Weighted-average shares for per share calculation, diluted	702.0	613.0	615.0	612.0
Loss per share, diluted (in dollars per share)	$ 0.51	$ (1.35)	$ (0.86)	$ (1.97)
Share-based awards
Anti-dilutive securities
Securities excluded from earnings per share calculation (in shares)	7.9	12.2	10.8	12.2