Employee Benefit Plans (Details 6) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	$ 8,720	$ 8,579	$ 7,304
U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	3,168	3,685
U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	4,655	4,245
U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	897	649
International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	3,577	3,503	3,235
International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,542	1,575
International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,849	1,754
International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	186	174
U.S equity [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,470	2,121
U.S equity [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,470	2,121
U.S equity [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
U.S equity [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
U.S equity [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	497	465
U.S equity [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	497	465
U.S equity [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
U.S equity [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
International Equity Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,203	1,405
International Equity Securities [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,203	1,405
International Equity Securities [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
International Equity Securities [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
International Equity Securities [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	693	721
International Equity Securities [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	693	721
International Equity Securities [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
International Equity Securities [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,633	2,068
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	14	5
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,619	2,063
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Collective Trusts Mutual Funds Equity [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	596	578
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	28	80
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	568	498
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Government [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	622	659
Government [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	146	19
Government [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	476	640
Government [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Government [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	635	568
Government [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	25	38
Government [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	610	530
Government [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Corporate [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	338	314
Corporate [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Corporate [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	338	314
Corporate [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Corporate [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	319	351
Corporate [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	16	24
Corporate [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	276	299
Corporate [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	27	28
Mortgage Backed Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	107	82
Mortgage Backed Securities [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mortgage Backed Securities [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	107	82
Mortgage Backed Securities [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mortgage Backed Securities [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2	2
Mortgage Backed Securities [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mortgage Backed Securities [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mortgage Backed Securities [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2	2
Other Asset Backed Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	61	74
Other Asset Backed Securities [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Other Asset Backed Securities [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	61	74
Other Asset Backed Securities [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Other Asset Backed Securities [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	5	16
Other Asset Backed Securities [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Other Asset Backed Securities [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	5	16
Other Asset Backed Securities [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Collective Trusts Mutual Funds Debt Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,046	1,064
Collective Trusts Mutual Funds Debt Securities [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Collective Trusts Mutual Funds Debt Securities [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,046	1,064
Collective Trusts Mutual Funds Debt Securities [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Collective Trusts Mutual Funds Debt Securities [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	345	332
Collective Trusts Mutual Funds Debt Securities [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	61	19
Collective Trusts Mutual Funds Debt Securities [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	284	313
Collective Trusts Mutual Funds Debt Securities [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mixed Funds [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	10	9
Mixed Funds [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	10	9
Mixed Funds [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mixed Funds [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Mixed Funds [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	102	105
Mixed Funds [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	13	16
Mixed Funds [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	89	89
Mixed Funds [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Real Estate [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	843	596
Real Estate [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Real Estate [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Real Estate [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	843	596
Real Estate [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	155	142
Real Estate [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Real Estate [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Real Estate [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	155	142
Cash And Cash Equivalents [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	404	213
Cash And Cash Equivalents [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	404	213
Cash And Cash Equivalents [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Cash And Cash Equivalents [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Cash And Cash Equivalents [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	211	217
Cash And Cash Equivalents [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	211	217
Cash And Cash Equivalents [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Cash And Cash Equivalents [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	0
Other Plan Assets [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	(17)	(26)
Other Plan Assets [Member] | U.S. [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	(79)	(87)
Other Plan Assets [Member] | U.S. [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	8	8
Other Plan Assets [Member] | U.S. [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	54	53
Other Plan Assets [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	17	6
Other Plan Assets [Member] | International [Member] | Prices in Active Markets for identical assets (Level 1) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	(2)	(5)
Other Plan Assets [Member] | International [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	17	9
Other Plan Assets [Member] | International [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	$ 2	$ 2