Statement of Consolidated Shareholders' Equity (USD $) In Millions, unless otherwise specified	Total	Series D Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2011	$ 28,993	$ 1,227	$ 241	$ 9,066	$ 18,500	$ (32)	$ (9)
NET INCOME	1,153				1,153
Commodity hedges, net of tax	20						20
Dividends:
Preferred	(38)				(38)
Common ($0.34 and $0.40 per share for 2012 and 2013 respectively)	(131)				(131)
Common shares issued	602		4	598
Common stock activity, net	(15)			(15)
Treasury stock activity, net	3			1		2
Compensation expense	86			86
Balance at Jun. 30, 2012	30,673	1,227	245	9,736	19,484	(30)	11
Balance at Dec. 31, 2012	31,331	1,227	245	9,859	20,161	(30)	(131)
NET INCOME	1,752				1,752
Commodity hedges, net of tax	13						13
Dividends:
Preferred	(38)				(38)
Common ($0.34 and $0.40 per share for 2012 and 2013 respectively)	(157)				(157)
Common stock activity, net	(17)		1	(18)
Treasury stock activity, net	(250)					(250)
Compensation expense	87			87
Balance at Jun. 30, 2013	$ 32,721	$ 1,227	$ 246	$ 9,928	$ 21,718	$ (280)	$ (118)