CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Changes in unamortized net pension and other postretirement benefit loss, tax expense (benefit)	$ (243)	$ 66	$ (154)
Changes in unamortized prior service credit, tax expense (benefit)	49	(9)	3
Reclassification of gains, tax expense	$ 0	$ 0	$ 1