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, 2011	$ 7,590	$ 2,831	$ 2,680
Stock compensation/issued for benefit plans	21
Retirement of common stock/cancellation of shares	(300)
Net income (loss)		564		564
Dividends declared: Common (2013 - $0.240; 2012 - $0.160)		(46)
Other comprehensive income (loss), net of tax			700	700
Balance as of end-of-period at Jun. 30, 2012	7,311	3,349	3,380	14,040
Balance as of beginning-of-year at Dec. 31, 2012	7,121	4,044	3,808	14,973
Stock compensation/issued for benefit plans	18
Retirement of common stock/cancellation of shares	(202)	(48)
Net income (loss)		556		556
Dividends declared: Common (2013 - $0.240; 2012 - $0.160)		(65)
Other comprehensive income (loss), net of tax			(1,915)	(1,915)
Balance as of end-of-period at Jun. 30, 2013	$ 6,937	$ 4,487	$ 1,893	$ 13,317