Fresh Start Accounting - Reorganization Items, Net (Details) - USD ($) $ in Millions		1 Months Ended	11 Months Ended	12 Months Ended
	Feb. 09, 2021	Feb. 09, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reorganization, Chapter 11 [Line Items]
Total reorganization items, net		$ 5,569	$ 0	$ (796)	$ 0
Reorganization Adjustments
Reorganization, Chapter 11 [Line Items]
Gains on the settlement of liabilities subject to compromise		6,443	0	12	0
Accrual for allowed claims		(1,002)	0	(879)	0
Write off of unamortized debt premiums (discounts)		0	0	518	0
Write off of unamortized debt issuance costs		0	0	(61)	0
Gain on fresh start adjustments		201	0	0	0
Gain from release of commitment liabilities		55	0	0	0
Debt and equity financing fees		0	0	(145)	0
Loss on divested assets		0	0	(128)	0
Legal and professional fees		(60)	0	(113)	0
Success fees for professional service providers		(38)	0	0	0
Surrender of other receivable	$ (18)	(18)	0	0	0
FLLO alternative transaction fee		(12)	0	0	0
Total reorganization items, net	$ (6,370)	$ 5,569	$ 0	$ (796)	$ 0