Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 739	$ 741	$ 1,369	$ 1,252
Other comprehensive income, net of income taxes:
Defined benefit and other postretirement plans adjustments	6	(1)	14	(1)
Other	(1)	2	(2)	4
Other comprehensive income, net of income taxes	5	1	12	3
Comprehensive income	744	742	1,381	1,255
Comprehensive income attributable to noncontrolling interest	(2)	(2)	(5)	(2)
Comprehensive income attributable to company shareholders	$ 742	$ 740	$ 1,376	$ 1,253