Consolidated Statements Of Stockholders' Equity - USD ($) $ in Millions	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Preferred Stock [Member] Series C Preferred Stock [Member]	Preferred Stock [Member] Series D Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2019	$ (203)				$ 5,162	$ 8,854	$ 5,673
Stock compensation/issued for benefit plans					48
Net income (loss)						499		$ 499
Retirement of common stock/cancellation of shares					(128)	(147)
Common stock dividends declared						(317)
Total other comprehensive income (loss), net of tax							3,258	3,258
Balance at Dec. 31, 2020					5,082	8,686	8,931	22,699
Stock compensation/issued for benefit plans					85
Net income (loss)						1,405		1,405
Retirement of common stock/cancellation of shares					(432)	(673)
Common stock dividends declared						(322)
Total other comprehensive income (loss), net of tax							(2,490)	(2,490)
Balance at Dec. 31, 2021					4,735	9,096	6,441	20,272
Issuance of preferred stock		$ 493	$ 493
Stock compensation/issued for benefit plans					40
Net income (loss)						(2,227)		(2,227)
Retirement of common stock/cancellation of shares					(231)	(319)
Common stock dividends declared						(311)
Total other comprehensive income (loss), net of tax							(14,109)	(14,109)
Balance at Dec. 31, 2022				$ 986	$ 4,544	$ 6,239	$ (7,668)	$ 4,101