Condensed Consolidated Statement of Changes in Equity (unaudited) - USD ($) $ in Millions	Total	Preferred stock dividends — Series B	Preferred stock dividends — Series C	Common stock and paid-in capital	Preferred stock	Retained earnings (accumulated deficit)	Retained earnings (accumulated deficit) Preferred stock dividends — Series B	Retained earnings (accumulated deficit) Preferred stock dividends — Series C	Accumulated other comprehensive loss	Treasury stock
Beginning balance at Dec. 31, 2021	$ 17,050			$ 21,671	$ 2,324	$ (1,599)			$ (158)	$ (5,188)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,436					1,436
Preferred stock dividends		$ (48)	$ (35)				$ (48)	$ (35)
Share-based compensation	110			110
Other comprehensive loss	(4,182)								(4,182)
Common stock repurchases	(1,599)									(1,599)
Common stock dividends	(298)					(298)
Ending balance at Sep. 30, 2022	12,434			21,781	2,324	(544)			(4,340)	(6,787)
Beginning balance at Jun. 30, 2022	13,984			21,762	2,324	(721)			(3,009)	(6,372)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	299					299
Preferred stock dividends		(16)	(11)				(16)	(11)
Share-based compensation	19			19
Other comprehensive loss	(1,331)								(1,331)
Common stock repurchases	(415)									(415)
Common stock dividends	(95)					(95)
Ending balance at Sep. 30, 2022	12,434			21,781	2,324	(544)			(4,340)	(6,787)
Beginning balance at Dec. 31, 2022	12,859			21,816	2,324	(384)			(4,059)	(6,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	944					944
Preferred stock dividends		(48)	(35)				(48)	(35)
Share-based compensation	120			120
Other comprehensive loss	(706)								(706)
Common stock repurchases	(29)									(29)
Common stock dividends	(280)					(280)
Ending balance at Sep. 30, 2023	12,825			21,936	2,324	197			(4,765)	(6,867)
Beginning balance at Jun. 30, 2023	13,532			21,915	2,324	23			(3,863)	(6,867)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	296					296
Preferred stock dividends		$ (16)	$ (11)				$ (16)	$ (11)
Share-based compensation	21			21
Other comprehensive loss	(902)								(902)
Common stock dividends	(95)					(95)
Ending balance at Sep. 30, 2023	$ 12,825			$ 21,936	$ 2,324	$ 197			$ (4,765)	$ (6,867)