CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Preferred stock	Total common equity	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss
Balance at beginning of period at Dec. 31, 2024		$ 265		$ 0	$ 12,727	$ 1,269	$ (1,772)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans					(7)
Net income	$ 201					201
Other comprehensive income (loss), net of tax	113						113
Balance at end of period at Mar. 31, 2025	12,796	265	$ 12,531	0	12,720	1,470	(1,659)
Balance at beginning of period at Dec. 31, 2025	12,439	265		0	12,701	852	(1,379)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans					(14)
Net income	291					291
Other comprehensive income (loss), net of tax	(65)						(65)
Balance at end of period at Mar. 31, 2026	$ 12,651	$ 265	$ 12,386	$ 0	$ 12,687	$ 1,143	$ (1,444)