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					25
Net income (loss)						219		219
Retirement of common stock/cancellation of shares					(50)	(55)
Common stock dividends declared						(81)
Total other comprehensive income (loss), net of tax							(3,170)	(3,170)
Balance at Mar. 31, 2021					5,057	8,769	5,761	19,587
Balance at Dec. 31, 2020					5,082	8,686	8,931	22,699
Net income (loss)								864
Balance at Jun. 30, 2021					5,021	9,242	7,479	21,742
Balance at Dec. 31, 2020					5,082	8,686	8,931	22,699
Net income (loss)								1,180
Balance at Sep. 30, 2021					4,956	9,360	6,849	21,165
Balance at Dec. 31, 2020					5,082	8,686	8,931	22,699
Stock compensation/issued for benefit plans					85
Net income (loss)						1,887		1,887
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	9,578	6,441	20,754
Balance at Mar. 31, 2021					5,057	8,769	5,761	19,587
Stock compensation/issued for benefit plans					23
Net income (loss)						645		645
Retirement of common stock/cancellation of shares					(59)	(91)
Common stock dividends declared						(81)
Total other comprehensive income (loss), net of tax							1,718	1,718
Balance at Jun. 30, 2021					5,021	9,242	7,479	21,742
Stock compensation/issued for benefit plans					16
Net income (loss)						316		316
Retirement of common stock/cancellation of shares					(81)	(119)
Common stock dividends declared						(79)
Total other comprehensive income (loss), net of tax							(630)	(630)
Balance at Sep. 30, 2021					4,956	9,360	6,849	21,165
Net income (loss)								708
Total other comprehensive income (loss), net of tax								(408)
Balance at Dec. 31, 2021					4,735	9,578	6,441	20,754
Stock compensation/issued for benefit plans					6
Net income (loss)						92		92
Retirement of common stock/cancellation of shares					(155)	(245)
Common stock dividends declared						(79)
Total other comprehensive income (loss), net of tax							(5,189)	(5,189)
Balance at Mar. 31, 2022					4,586	9,346	1,252	15,184
Balance at Dec. 31, 2021					4,735	9,578	6,441	20,754
Net income (loss)								319
Balance at Jun. 30, 2022					4,546	9,445	(4,337)	9,654
Balance at Dec. 31, 2021					4,735	9,578	6,441	20,754
Net income (loss)								(2,264)
Balance at Sep. 30, 2022					4,534	6,762	(8,628)	2,668
Balance at Dec. 31, 2021					4,735	9,578	6,441	20,754
Issuance of preferred stock		$ 493	$ 493
Stock compensation/issued for benefit plans					40
Net income (loss)						(2,241)		(2,241)
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	6,707	(7,668)	4,569
Balance at Mar. 31, 2022					4,586	9,346	1,252	15,184
Stock compensation/issued for benefit plans					9
Net income (loss)						228		228
Retirement of common stock/cancellation of shares					(49)	(51)
Common stock dividends declared						(78)
Total other comprehensive income (loss), net of tax							(5,589)	(5,589)
Balance at Jun. 30, 2022					4,546	9,445	(4,337)	9,654
Stock compensation/issued for benefit plans					15
Net income (loss)						(2,583)		(2,583)
Retirement of common stock/cancellation of shares					(27)	(23)
Common stock dividends declared						(77)
Total other comprehensive income (loss), net of tax							(4,291)	(4,291)
Balance at Sep. 30, 2022					4,534	6,762	(8,628)	2,668
Net income (loss)								21
Total other comprehensive income (loss), net of tax								960
Balance at Dec. 31, 2022				$ 986	$ 4,544	$ 6,707	$ (7,668)	$ 4,569