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, 2012	$ 7,121	$ 4,044	$ 3,808
Stock compensation/issued for benefit plans	10
Retirement of common stock/cancellation of shares	(88)	(12)
Net income (loss)		239		239
Common stock dividends declared (2014 - $0.160; 2013 - $0.120)		(33)
Other comprehensive income (loss), net of tax			(227)	(227)
Balance as of end-of-year at Mar. 31, 2013	7,043	4,238	3,581	14,862
Balance as of beginning-of-year at Dec. 31, 2013	6,876	5,013	1,563	13,452
Stock compensation/issued for benefit plans	7
Retirement of common stock/cancellation of shares	(78)	(72)
Net income (loss)		329		329
Common stock dividends declared (2014 - $0.160; 2013 - $0.120)		(42)
Other comprehensive income (loss), net of tax			890	890
Balance as of end-of-year at Mar. 31, 2014	$ 6,805	$ 5,228	$ 2,453	$ 14,486