Pension and Postretirement Benefit Plans (Details 6) (USD $) In Millions, unless otherwise specified				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended								12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended					12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended
	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits	Dec. 31, 2009 United States Qualified and Non-qualified Pension Benefits	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Level 3	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Equities	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Equities	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Equities Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Equities Level 3	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Fixed Income	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Fixed Income	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Fixed Income Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Fixed Income Level 3	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Private Equity	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Private Equity	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Private Equity Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Private Equity Level 3	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Absolute Return	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Absolute Return	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Absolute Return Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Absolute Return Level 3	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Commodities	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Commodities	Dec. 31, 2011 United States Qualified and Non-qualified Pension Benefits Commodities Level 3	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits Commodities Level 3	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Level 3	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Level 3	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Equities	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Equities	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Equities Level 3	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Equities Level 3	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Fixed Income	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Fixed Income	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Fixed Income Level 3	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Fixed Income Level 3	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Private Equity	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Private Equity	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Private Equity Level 3	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Private Equity Level 3	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Absolute Return	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Absolute Return	Dec. 31, 2011 International Qualified and Non-qualified Pension Benefits Absolute Return Level 3	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits Absolute Return Level 3	Dec. 31, 2011 Postretirement Benefits	Dec. 31, 2010 Postretirement Benefits	Dec. 31, 2009 Postretirement Benefits	Dec. 31, 2011 Postretirement Benefits Level 3	Dec. 31, 2010 Postretirement Benefits Level 3	Dec. 31, 2011 Postretirement Benefits Equities	Dec. 31, 2010 Postretirement Benefits Equities	Dec. 31, 2011 Postretirement Benefits Equities Level 3	Dec. 31, 2010 Postretirement Benefits Equities Level 3	Dec. 31, 2011 Postretirement Benefits Fixed Income	Dec. 31, 2010 Postretirement Benefits Fixed Income	Dec. 31, 2011 Postretirement Benefits Fixed Income Level 3	Dec. 31, 2010 Postretirement Benefits Fixed Income Level 3	Dec. 31, 2011 Postretirement Benefits Private Equity	Dec. 31, 2010 Postretirement Benefits Private Equity	Dec. 31, 2011 Postretirement Benefits Private Equity Level 3	Dec. 31, 2010 Postretirement Benefits Private Equity Level 3	Dec. 31, 2011 Postretirement Benefits Absolute Return	Dec. 31, 2010 Postretirement Benefits Absolute Return	Dec. 31, 2011 Postretirement Benefits Absolute Return Level 3	Dec. 31, 2010 Postretirement Benefits Absolute Return Level 3	Dec. 31, 2011 Postretirement Benefits Commodities	Dec. 31, 2010 Postretirement Benefits Commodities	Dec. 31, 2011 Postretirement Benefits Commodities Level 3	Dec. 31, 2010 Postretirement Benefits Commodities Level 3
Summary of changes in fair values of level 3 assets
Fair value, beginning balance	$ 12,102	$ 11,575	$ 10,493	$ 3,459	$ 3,115	$ 3,339	$ 3,882	$ 506	$ 4	$ 4,014	$ 2,904	$ 144	$ 185	$ 2,063	$ 2,079	$ 2,075	$ 1,961	$ 1,755	$ 1,765	$ 623	$ 728	$ 540	$ 449	$ 111	$ 237	$ 4,355	$ 3,897	$ 546	$ 470	$ 1,676	$ 1,774	$ 98	$ 14	$ 2,127	$ 1,789	$ 34	$ 22	$ 155	$ 88	$ 70	$ 59	$ 602	$ 527	$ 344	$ 375	$ 1,209	$ 1,149	$ 1,075	$ 269	$ 280	$ 512	$ 522	$ 16		$ 377	$ 308	$ 4	$ 6	$ 187	$ 226	$ 226	$ 245	$ 57	$ 56	$ 20	$ 22	$ 18	$ 14	$ 3	$ 7
Net transfers into / (out of) level 3				(54)	(150)				49			5	(37)				27			(59)	(49)				(140)			(96)	114			(93)	97				17			(21)				18					(2)	(5)				2				(2)							(2)	(1)				(4)
Foreign currency exchange																										(74)	18	(12)	(12)				2			(1)				(1)	4			(10)	(18)
Purchases, sales, issuances and settlements, net				(254)	122			(52)	412			(97)	(34)			(108)	(55)			3	(201)							20	2				(15)							17	7			3	10				(46)	(5)			(1)	13			(3)	(1)			(43)	(11)			1	(6)
Realized gain (loss)				(21)	138			3				21	1			(50)	133			5	4							1	(21)				(18)								(3)			1					(30)	16							1				(31)	16
Change in unrealized gains/(losses) relating to instruments sold during the period				72				(8)				(17)				133				(36)																													17				(1)				(1)				20				(1)
Change in unrealized gains/(losses) relating to instruments still held at the reporting date				1	234			(7)	41			18	29			12	9			(16)	141			(6)	14			22	(7)				18			6	(5)			2	3			14	(23)				16	(17)				1			1	1			15	(24)			(1)	5			1
Fair value, ending balance	$ 12,102	$ 11,575	$ 10,493	$ 3,203	$ 3,459	$ 3,339	$ 3,882	$ 442	$ 506	$ 4,014	$ 2,904	$ 74	$ 144	$ 2,063	$ 2,079	$ 2,062	$ 2,075	$ 1,755	$ 1,765	$ 520	$ 623	$ 540	$ 449	$ 105	$ 111	$ 4,643	$ 4,355	$ 481	$ 546	$ 1,676	$ 1,774	$ 5	$ 98	$ 2,127	$ 1,789	$ 39	$ 34	$ 155	$ 88	$ 67	$ 70	$ 602	$ 527	$ 370	$ 344	$ 1,209	$ 1,149	$ 1,075	$ 224	$ 269	$ 512	$ 522	$ 14	$ 16	$ 377	$ 308	$ 2	$ 4	$ 187	$ 226	$ 187	$ 226	$ 57	$ 56	$ 17	$ 20	$ 18	$ 14	$ 4	$ 3