Consolidated Statements Of Stockholders' Equity - USD ($) $ in Millions	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2020	$ 5,082	$ 8,686	$ 8,931
Stock compensation/issued for benefit plans	48
Net income (loss)		867		$ 867
Retirement of common stock/cancellation of shares	(109)	(146)
Common stock dividends declared		(162)
Other comprehensive income (loss), net of tax			(1,452)	(1,452)
Balance at Jun. 30, 2021	5,021	9,245	7,479	21,745
Balance at Mar. 31, 2021	5,057	8,775	5,761
Stock compensation/issued for benefit plans	23
Net income (loss)		642		642
Retirement of common stock/cancellation of shares	(59)	(91)
Common stock dividends declared		(81)
Other comprehensive income (loss), net of tax			1,718	1,718
Balance at Jun. 30, 2021	5,021	9,245	7,479	21,745
Balance at Dec. 31, 2021	4,735	9,096	6,441	20,272
Stock compensation/issued for benefit plans	15
Net income (loss)		341		341
Retirement of common stock/cancellation of shares	(204)	(296)
Common stock dividends declared		(156)
Other comprehensive income (loss), net of tax			(10,784)	(10,784)
Balance at Jun. 30, 2022	4,546	8,985	(4,343)	9,188
Balance at Mar. 31, 2022	4,586	8,876	1,250
Stock compensation/issued for benefit plans	9
Net income (loss)		238		238
Retirement of common stock/cancellation of shares	(49)	(51)
Common stock dividends declared		(78)
Other comprehensive income (loss), net of tax			(5,593)	(5,593)
Balance at Jun. 30, 2022	$ 4,546	$ 8,985	$ (4,343)	$ 9,188