Fair Value Measurements (Non-U.S. Plans) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Cash	$ 233
Fair value plan assets	1,806	1,513	1,343
Level 1
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	20	38
Level 1 | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	194	172
Level 1 | Common stock and equivalents
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	20	38
Level 1 | Common stock and equivalents | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	194	172
Level 1 | Commingled equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 1 | Commingled equity funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 1 | Government, agency, and government-sponsored enterprise obligations
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 1 | Government, agency, and government-sponsored enterprise obligations | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 1 | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 1 | Corporate bonds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 1 | Commingled bond funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 1 | Commingled bond funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 1 | Commingled short-term investment funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 1 | Commingled short-term investment funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 2
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	143	123
Level 2 | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	1,319	1,240
Level 2 | Common stock and equivalents
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	0
Level 2 | Common stock and equivalents | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	0	0
Level 2 | Commingled equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	13	55
Level 2 | Commingled equity funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	569	558
Level 2 | Government, agency, and government-sponsored enterprise obligations
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	11	6
Level 2 | Government, agency, and government-sponsored enterprise obligations | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	26	21
Level 2 | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	18	9
Level 2 | Corporate bonds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	316	289
Level 2 | Commingled bond funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	49
Level 2 | Commingled bond funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	399	361
Level 2 | Commingled short-term investment funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	99	3
Level 2 | Commingled short-term investment funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	9	11
Level 3 | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		26
Level 3 | Common stock and equivalents | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		0
Level 3 | Commingled equity funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		0
Level 3 | Government, agency, and government-sponsored enterprise obligations | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		3
Level 3 | Corporate bonds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		23
Level 3 | Commingled bond funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		0
Level 3 | Commingled short-term investment funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities		0
Total
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	163	161
Total | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	1,513	1,438
Accrued income receivable	5	61
Fair value plan assets	1,806	1,513
Total | Common stock and equivalents
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	20	38
Total | Common stock and equivalents | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	194	172
Total | Commingled equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	13	55
Total | Commingled equity funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	569	558
Total | Government, agency, and government-sponsored enterprise obligations
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	11	6
Total | Government, agency, and government-sponsored enterprise obligations | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	26	24
Total | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	18	9
Total | Corporate bonds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	316	312
Total | Commingled bond funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	0	49
Total | Commingled bond funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	399	361
Total | Commingled short-term investment funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value plan assets	99	3
Total | Commingled short-term investment funds | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	9	11
Total | Insurance contracts | Non - U.S. Pension Benefit
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total marketable securities	$ 55	$ 14