Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred Stock	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Shares, Issued at Dec. 31, 2019		0	1,642,488,911
Total stockholders' equity at Dec. 31, 2019		$ 0	$ 16	$ (1,717)	$ 17,561	$ (2,253)	$ 270
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance (Shares)		10,062,500	29,382,500
Stock-based compensation (Shares)			7,556,798
Stock issuance (Par value)			$ 0
Preferred stock issuance (Value in excess of par)					975
Common stock issuance (Value in excess of par)					975
Stock-based compensation					176
Net income (loss)	$ (292)					(292)
Cumulative effect adjustment for adoption of ASU 2016-13	10					(10)
Preferred stock dividends						(19)
Total other comprehensive income (loss)	(119)						(119)
Ending Balance (Shares Issued) at Sep. 30, 2020		10,062,500	1,679,428,209
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2020	15,564	$ 0	$ 17	(1,717)	19,687	(2,574)	151
Shares, Issued at Jun. 30, 2020		10,062,500	1,676,753,566
Total stockholders' equity at Jun. 30, 2020		$ 0	$ 17	(1,717)	19,590	(2,405)	131
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (Shares)			2,674,643
Stock-based compensation					97
Net income (loss)	(155)					(155)
Preferred stock dividends						(14)
Total other comprehensive income (loss)	20						20
Ending Balance (Shares Issued) at Sep. 30, 2020		10,062,500	1,679,428,209
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2020	15,564	$ 0	$ 17	(1,717)	19,687	(2,574)	151
Shares, Issued at Dec. 31, 2020		10,062,500	1,679,911,918
Total stockholders' equity at Dec. 31, 2020	15,326	$ 0	$ 17	(2,251)	19,732	(2,378)	207
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (Shares)			8,111,720
Stock-based compensation					199
Net income (loss)	946					946
Preferred stock dividends						(42)
Total other comprehensive income (loss)	31						31
Ending Balance (Shares Issued) at Sep. 30, 2021		10,062,500	1,688,023,638
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2021	16,462	$ 0	$ 17	(2,251)	19,930	(1,473)	238
Shares, Issued at Jun. 30, 2021		10,062,500	1,685,006,608
Total stockholders' equity at Jun. 30, 2021		$ 0	$ 17	(2,251)	19,817	(1,878)	237
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (Shares)			3,017,030
Stock-based compensation					113
Net income (loss)	419					419
Preferred stock dividends						(14)
Total other comprehensive income (loss)	1						1
Ending Balance (Shares Issued) at Sep. 30, 2021		10,062,500	1,688,023,638
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2021	$ 16,462	$ 0	$ 17	$ (2,251)	$ 19,930	$ (1,473)	$ 238