Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Consolidated Statements of Comprehensive Income
Net income attributable to common stock	$ 4,598		$ 6,771		$ 4,530
Other comprehensive income (loss) items:
Foreign currency translation (losses) gains	(25)		(11)		4
Unrealized gains on derivatives	16	[1]	14	[1]	37	[1]
Pension and postretirement gains (losses)	14	[2]	(60)	[2]	(52)	[2]
Reclassification to income of realized (gains) losses on derivatives	(24)	[3]	98	[3]	83	[3]
Other comprehensive income (loss), net of tax	(19)	[4]	41	[4]	72	[4]
Comprehensive income attributable to common stock	$ 4,579		$ 6,812		$ 4,602

[1] Net of tax of $(9), $(7) and $(20) in 2012, 2011 and 2010, respectively.

[2] Net of tax of $(8), $34 and $30 in 2012, 2011 and 2010, respectively.

[3] Net of tax of $14, $(56) and $(47) in 2012, 2011 and 2010, respectively.

[4] There were no other comprehensive income (loss) items related to noncontrolling interests in 2012, 2011 and 2010.