Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance as of beginning-of-year at Dec. 31, 2023		$ 986	$ 4,605	$ 4,778	$ (3,476)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation/issued for benefit plans			19
Net income (loss)	$ 1,222			1,222
Preferred stock dividends declared				(34)
Common stock dividends declared				(79)
Other comprehensive income (loss), net of tax	(475)				(475)
Balance as of end-of-period at Mar. 31, 2024	7,546	986	4,624	5,887	(3,951)
Balance as of beginning-of-year at Dec. 31, 2024	8,269	986	4,674	7,645	(5,036)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation/issued for benefit plans			29
Net income (loss)	(722)			(722)
Preferred stock dividends declared				(34)
Common stock dividends declared				(79)
Other comprehensive income (loss), net of tax	730				730
Balance as of end-of-period at Mar. 31, 2025	$ 8,193	$ 986	$ 4,703	$ 6,810	$ (4,306)