Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 426	$ 393	$ 809	$ 810
Postretirement and postemployment plans
Change in actuarial loss and other	133	(3)	146	10
Income tax (provision) benefit on postretirement and postemployment plans	(49)	1	(54)	(4)
Postretirement and postemployment plans, net of tax	(84)	2	(92)	(6)
Foreign currency translation and other
Unrealized loss	(3)	(1)	(4)	0
Income tax benefit on foreign currency translation and other	1	0	1	0
Foreign currency translation and other, net of tax	(2)	(1)	(3)	0
Other comprehensive income (loss)	82	(3)	89	6
Comprehensive income	$ 508	$ 390	$ 898	$ 816