Employee Benefit Plans (Details 6) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value Measurements of Company's Pension Plans
Investment in company's common stock	$ 28		$ 27
U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	11,210		9,909		8,720
U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	4,260		3,704
U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	5,631		5,036
U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,319		1,169
International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	4,543		4,125		3,577
International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,425		1,552
International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,796		2,362
International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	322		211
U.S equity [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,298	[1]	1,709	[1]
U.S equity [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,298	[1]	1,709	[1]
U.S equity [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[1]	0	[1]
U.S equity [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[1]	0	[1]
U.S equity [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	409	[1]	334	[1]
U.S equity [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	409	[1]	334	[1]
U.S equity [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[1]	0	[1]
U.S equity [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[1]	0	[1]
International Equity Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,501		1,263
International Equity Securities [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,501		1,263
International Equity Securities [Member] | U.S. [Member] | 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] | 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	533		520
International Equity Securities [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	533		520
International Equity Securities [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
International Equity Securities [Member] | International [Member] | 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	2,977	[2]	2,979	[2]
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	26	[2]	7	[2]
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2,951	[2]	2,972	[2]
Collective Trusts Mutual Funds Equity [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[2]	0	[2]
Collective Trusts Mutual Funds Equity [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,066	[2]	1,233	[2]
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	211	[2]	402	[2]
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	855	[2]	831	[2]
Collective Trusts Mutual Funds Equity [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[2]	0	[2]
Government [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	81		435
Government [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	52		396
Government [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	29		39
Government [Member] | U.S. [Member] | 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	726		578
Government [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	46		40
Government [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	680		538
Government [Member] | International [Member] | 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	1,275		384
Corporate [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Corporate [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,275		384
Corporate [Member] | U.S. [Member] | 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	545		230
Corporate [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	23		25
Corporate [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	499		175
Corporate [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	23		30
Mortgage-Backed Securities [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1		65
Mortgage-Backed Securities [Member] | U.S. [Member] | 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] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1		65
Mortgage-Backed Securities [Member] | U.S. [Member] | 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	4		2
Mortgage-Backed Securities [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Mortgage-Backed Securities [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2		0
Mortgage-Backed Securities [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	2		2
Other Asset Backed [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		51
Other Asset Backed [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Other Asset Backed [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		51
Other Asset Backed [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Other Asset Backed [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		4
Other Asset Backed [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Other Asset Backed [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		4
Other Asset Backed [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Collective Trusts/Mutual Funds [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,357	[2]	1,520	[2]
Collective Trusts/Mutual Funds [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[2]	0	[2]
Collective Trusts/Mutual Funds [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,357	[2]	1,520	[2]
Collective Trusts/Mutual Funds [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[2]	0	[2]
Collective Trusts/Mutual Funds [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	647	[2]	671	[2]
Collective Trusts/Mutual Funds [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	27	[2]	26	[2]
Collective Trusts/Mutual Funds [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	620	[2]	645	[2]
Collective Trusts/Mutual Funds [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[2]	0	[2]
Mixed Funds [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[3]	0	[3]
Mixed Funds [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[3]	0	[3]
Mixed Funds [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[3]	0	[3]
Mixed Funds [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[3]	0	[3]
Mixed Funds [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	120	[3]	115	[3]
Mixed Funds [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	5	[3]	4	[3]
Mixed Funds [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	115	[3]	111	[3]
Mixed Funds [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[3]	0	[3]
Real Estate [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,265	[4]	1,114	[4]
Real Estate [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[4]	0	[4]
Real Estate [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[4]	0	[4]
Real Estate [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	1,265	[4]	1,114	[4]
Real Estate [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	294	[4]	177	[4]
Real Estate [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[4]	0	[4]
Real Estate [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0	[4]	0	[4]
Real Estate [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	294	[4]	177	[4]
Cash And Cash Equivalents [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	385		373
Cash And Cash Equivalents [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	385		373
Cash And Cash Equivalents [Member] | U.S. [Member] | 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] | 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	173		222
Cash And Cash Equivalents [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	173		204
Cash And Cash Equivalents [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		18
Cash And Cash Equivalents [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	0		0
Other [Member] | U.S. [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	70	[5]	16	[5]
Other [Member] | U.S. [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	(2)	[5]	(44)	[5]
Other [Member] | U.S. [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	18	[5]	5	[5]
Other [Member] | U.S. [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	54	[5]	55	[5]
Other [Member] | International [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	26	[5]	39	[5]
Other [Member] | International [Member] | Level 1 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	(2)	[5]	(3)	[5]
Other [Member] | International [Member] | Level 2 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	25	[5]	40	[5]
Other [Member] | International [Member] | Level 3 [Member]
Fair Value Measurements of Company's Pension Plans
Fair value of plan assets	$ 3	[5]	$ 2	[5]

[1] U.S. equities include investments in the company’s common stock in the amount of $28 at December 31, 2013, and $27 at December 31, 2012.

[2] Collective Trusts/Mutual Funds for U.S. plans are entirely index funds; for International plans, they are mostly index funds. For these index funds, the Level 2 designation is partially based on the restriction that advance notification of redemptions, typically two business days, is required.

[3] Mixed funds are composed of funds that invest in both equity and fixed-income instruments in order to diversify and lower risk.

[4] The year-end valuations of the U.S. real estate assets are based on internal appraisals by the real estate managers, which are updates of third-party appraisals that occur at least once a year for each property in the portfolio.

[5] The “Other” asset class includes net payables for securities purchased but not yet settled (Level 1); dividends and interest- and tax-related receivables (Level 2); insurance contracts and investments in private-equity limited partnerships (Level 3).