CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Millions, unless otherwise specified	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	RETAINED EARNINGS
Balance at Dec. 31, 2011		$ 619	$ 18,901	$ (1,012)	$ 2,319
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through dividend reinvestment, incentive and benefit plans		5	86
Repurchase of common stock		0	0
Shares withheld to satisfy tax withholdings		(1)	(17)
Share-based compensation and other, net			82
Other comprehensive income	28
Net income	544				544
Dividends declared					(1,357)
Balance at Sep. 30, 2012	20,197	623	19,052	(984)	1,506
Balance at Dec. 31, 2012	19,289	626	19,079	(1,701)	1,285
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through dividend reinvestment, incentive and benefit plans		2	50
Repurchase of common stock	(1,240)	(35)	(1,219)
Shares withheld to satisfy tax withholdings		0	(16)
Share-based compensation and other, net			60
Other comprehensive income	41			41
Net income	(478)				(478)
Dividends declared					(980)
Balance at Sep. 30, 2013	$ 16,714	$ 593	$ 17,954	$ (1,660)	$ (173)