Loss Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Loss (numerator)
Net loss	$ (55)	$ (10,298)	$ (1,548)
Net loss applicable to common stock for computing basic loss per common share	(55)	(10,298)	(1,548)
Net loss as adjusted for purposes of computing diluted loss per common share	$ (55)	$ (10,298)	$ (1,548)
Weighted-average number of shares:
Outstanding during period (in shares)	1,014,554	1,006,787	1,028,069
Non-vested restricted stock (in shares)	(26,874)	(23,706)	(20,552)
Weighted average shares outstanding for computing basic loss per common share (in shares)	987,680	983,081	1,007,517
Incremental common shares attributable to dilutive securities:
Shares issuable under convertible securities (in shares)	0	0	0
Shares issuable under incentive compensation plans (in shares)	0	0	0
Number of shares as adjusted for purposes of computing diluted loss per common share (in shares)	987,680	983,081	1,007,517
Basic loss per common share (in dollars per share)	$ (0.06)	$ (10.48)	$ (1.54)
Diluted loss per common share (in dollars per share)	$ (0.06)	$ (10.48)	$ (1.54)
Stock Compensation Plan
Incremental common shares attributable to dilutive securities:
Number of shares of common stock excluded from the computation of diluted loss per share (in shares)	7,300	300	3,800
Restricted Stock
Incremental common shares attributable to dilutive securities:
Number of shares of common stock excluded from the computation of diluted loss per share (in shares)	16,000	22,500	13,800