Consolidated Statements Of Stockholders' Equity - USD ($) $ in Millions	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance as of beginning-of-year at Dec. 31, 2013	$ 6,876	$ 5,013	$ 1,563
Stock compensation/issued for benefit plans	51
Retirement of common stock/cancellation of shares	(231)	(219)
Net income (loss)		1,166		$ 1,166
Common stock dividends declared (2015 - $0.60; 2014 - $0.48)		(126)
Other comprehensive income (loss), net of tax			1,359	1,359
Balance as of end-of-period at Sep. 30, 2014	6,696	5,834	2,922	15,452
Balance as of beginning-of-year at Dec. 31, 2014	6,622	6,022	3,096	15,740
Stock compensation/issued for benefit plans	74
Retirement of common stock/cancellation of shares	(316)	(384)
Net income (loss)		871		871
Common stock dividends declared (2015 - $0.60; 2014 - $0.48)		(151)
Other comprehensive income (loss), net of tax			(1,433)	(1,433)
Balance as of end-of-period at Sep. 30, 2015	$ 6,380	$ 6,358	$ 1,663	$ 14,401