STATEMENTS OF CONSOLIDATED CHANGES IN EQUITY - USD ($) $ in Millions	Total	Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock	Cumulative Preferred Stock	Cumulative Preferred Stock Series C Preferred Stock	Cumulative Preferred Stock Series B and Series C Preferred Stock	Common Stock	Additional Paid-in-Capital	Additional Paid-in-Capital Series B and Series C Preferred Stock	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings (Accumulated Deficit) Series A Preferred Stock	Retained Earnings (Accumulated Deficit) Series B Preferred Stock	Retained Earnings (Accumulated Deficit) Series C Preferred Stock	Accumulated Other Comprehensive Loss
Balance, beginning of period (in shares) at Dec. 31, 2018					2,000,000
Balance, beginning of year at Dec. 31, 2018					$ 1,740			$ 5	$ 6,072		$ 349	$ 0				$ (108)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued (in shares)						0		0
Stock issued						$ 0		$ 0	0
Conversion of Series B Preferred Stock and Series C Preferred Stock (in shares)							0
Conversion of Series B Preferred Stock and Series C Preferred Stock							$ 0			$ 0
Balance, end of year (in shares) at Dec. 31, 2019	1,777,500	800,000	977,500	0	2,000,000
Balance, beginning of year (in shares) at Dec. 31, 2018								501,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance related to benefit and investment plans (in shares)								1,000,000
Issuances related to benefit and investment plans								$ 0	8
Recognition of beneficial conversion feature	$ 0								0
Net income (loss)	791										791
Common Stock dividends declared (see Note 13)											(433)
Preferred stock dividends declared													$ (24)	$ (51)	$ 0
Amortization of beneficial conversion feature	$ 0										0
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13 [Member]
Other comprehensive income																10
Balance, end of year (in shares) at Dec. 31, 2019								502,000,000
Balance, end of year at Dec. 31, 2019	$ 8,359				$ 1,740			$ 5	6,080		632	(7)				(98)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued (in shares)						1,000,000		48,000,000
Stock issued						$ 723		$ 1	672
Conversion of Series B Preferred Stock and Series C Preferred Stock (in shares)							0
Conversion of Series B Preferred Stock and Series C Preferred Stock							$ (100)			100
Balance, end of year (in shares) at Dec. 31, 2020	2,402,400	800,000	977,400	625,000	3,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance related to benefit and investment plans (in shares)								1,000,000
Issuances related to benefit and investment plans								$ 0	30
Recognition of beneficial conversion feature	$ 32								32
Net income (loss)	(773)										(773)
Common Stock dividends declared (see Note 13)											(480)
Preferred stock dividends declared													(73)	(85)	(27)
Amortization of beneficial conversion feature	$ (32)										(32)
Other comprehensive income																8
Balance, end of year (in shares) at Dec. 31, 2020	551,355,861							551,000,000
Balance, end of year at Dec. 31, 2020	$ 8,348				$ 2,363			$ 6	6,914		(845)	$ 0				(90)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued (in shares)						0		77,000,000
Stock issued						$ 0		$ 0	1
Conversion of Series B Preferred Stock and Series C Preferred Stock (in shares)							(2,000,000)
Conversion of Series B Preferred Stock and Series C Preferred Stock							$ (1,573)			$ 1,573
Balance, end of year (in shares) at Dec. 31, 2021	800,000	800,000	0	0	1,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance related to benefit and investment plans (in shares)								1,000,000
Issuances related to benefit and investment plans								$ 0	41
Recognition of beneficial conversion feature	$ 0								0
Net income (loss)	1,486										1,486
Common Stock dividends declared (see Note 13)											(404)
Preferred stock dividends declared													$ (49)	$ (34)	$ 0
Amortization of beneficial conversion feature	$ 0										0
Other comprehensive income																26
Balance, end of year (in shares) at Dec. 31, 2021	628,923,534							629,000,000
Balance, end of year at Dec. 31, 2021	$ 9,415				$ 790			$ 6	$ 8,529		$ 154					$ (64)