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	64
Net income (loss)		1,185		$ 1,185
Retirement of common stock/cancellation of shares	(190)	(265)
Common stock dividends declared		(241)
Other comprehensive income (loss), net of tax			(2,082)	(2,082)
Balance at Sep. 30, 2021	4,956	9,365	6,849	21,170
Balance at Jun. 30, 2021	5,021	9,245	7,479
Stock compensation/issued for benefit plans	16
Net income (loss)		318		318
Retirement of common stock/cancellation of shares	(81)	(119)
Common stock dividends declared		(79)
Other comprehensive income (loss), net of tax			(630)	(630)
Balance at Sep. 30, 2021	4,956	9,365	6,849	21,170
Balance at Dec. 31, 2021	4,735	9,096	6,441	20,272
Stock compensation/issued for benefit plans	30
Net income (loss)		(2,233)		(2,233)
Retirement of common stock/cancellation of shares	(231)	(319)
Common stock dividends declared		(233)
Other comprehensive income (loss), net of tax			(15,069)	(15,069)
Balance at Sep. 30, 2022	4,534	6,311	(8,628)	2,217
Balance at Jun. 30, 2022	4,546	8,985	(4,343)
Stock compensation/issued for benefit plans	15
Net income (loss)		(2,574)		(2,574)
Retirement of common stock/cancellation of shares	(27)	(23)
Common stock dividends declared		(77)
Other comprehensive income (loss), net of tax			(4,285)	(4,285)
Balance at Sep. 30, 2022	$ 4,534	$ 6,311	$ (8,628)	$ 2,217