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 [Abstract]
Net income	$ 3,943		$ 3,292		$ 2,780
Other comprehensive income/(loss):
Defined benefit plans	(145)		(301)		(88)
Foreign currency translation	12		(20)		7
Derivatives	1		1		1
Total other comprehensive loss	(132)	[1]	(320)	[1]	(80)	[1]
Comprehensive income	$ 3,811		$ 2,972		$ 2,700

[1] Net of deferred taxes of $82 million, $199 million, and $57 million during 2012, 2011, and 2010, respectively.