Condensed Consolidated Statement of Changes in Equity (unaudited) - USD ($) $ in Millions	Total	Series B Preferred Stock	Series C Preferred Stock	Common stock and paid-in capital	Preferred stock	Retained earnings (accumulated deficit)	Retained earnings (accumulated deficit) Series B Preferred Stock	Retained earnings (accumulated deficit) Series C Preferred Stock	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	1,137					1,137
Preferred stock dividends		$ (32)	$ (24)				$ (32)	$ (24)
Share-based compensation	91			91
Other comprehensive income (loss)	(2,851)								(2,851)
Common stock repurchases	(1,184)									(1,184)
Common stock dividends	(203)					(203)
Ending balance at Jun. 30, 2022	13,984			21,762	2,324	(721)			(3,009)	(6,372)
Beginning balance at Mar. 31, 2022	15,413			21,728	2,324	(1,076)			(1,791)	(5,772)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	482					482
Preferred stock dividends		(16)	(12)				(16)	(12)
Share-based compensation	34			34
Other comprehensive income (loss)	(1,218)								(1,218)
Common stock repurchases	(600)									(600)
Common stock dividends	(99)					(99)
Ending balance at Jun. 30, 2022	13,984			21,762	2,324	(721)			(3,009)	(6,372)
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	648					648
Preferred stock dividends		(32)	(24)				(32)	(24)
Share-based compensation	99			99
Other comprehensive income (loss)	196								196
Common stock repurchases	(29)									(29)
Common stock dividends	(185)					(185)
Ending balance at Jun. 30, 2023	13,532			21,915	2,324	23			(3,863)	(6,867)
Beginning balance at Mar. 31, 2023	13,378			21,880	2,324	(185)			(3,776)	(6,865)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	329					329
Preferred stock dividends		$ (16)	$ (12)				$ (16)	$ (12)
Share-based compensation	35			35
Other comprehensive income (loss)	(87)								(87)
Common stock repurchases	(2)									(2)
Common stock dividends	(93)					(93)
Ending balance at Jun. 30, 2023	$ 13,532			$ 21,915	$ 2,324	$ 23			$ (3,863)	$ (6,867)