Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 1,454	$ 2,209
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	256	84
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	43	110
Fair value on a recurring basis | Fair Value | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	229	75
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	36	103
Fair value on a recurring basis | Fair Value | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet		1
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	4
Fair value on a recurring basis | Fair Value | Interest rate swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	27	8
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	3	7
Fair value on a recurring basis | Fair Value | U.S. government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	108	234
Fair value on a recurring basis | Fair Value | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	95	125
Fair value on a recurring basis | Fair Value | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	619	781
Fair value on a recurring basis | Fair Value | Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	41	40
Fair value on a recurring basis | Fair Value | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		60
Fair value on a recurring basis | Fair Value | Asset-backed securities Automobile loan related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	282	585
Fair value on a recurring basis | Fair Value | Asset-backed securities Credit card related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	162	180
Fair value on a recurring basis | Fair Value | Asset-backed securities Equipment lease related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	48	67
Fair value on a recurring basis | Fair Value | Asset-backed securities Other asset-backed securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	46	75
Fair value on a recurring basis | Fair Value | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	38	49
Fair value on a recurring basis | Fair Value | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	15	2
Fair value on a recurring basis | Fair Value | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		11
Fair value on a recurring basis | Fair Value | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	1	2
Fair value on a recurring basis | Level 1 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	0	0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0	0
Fair value on a recurring basis | Level 1 | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet		0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0
Fair value on a recurring basis | Level 1 | Interest rate swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	0	0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0	0
Fair value on a recurring basis | Level 1 | U.S. government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		0
Fair value on a recurring basis | Level 1 | Asset-backed securities Automobile loan related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Asset-backed securities Credit card related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Asset-backed securities Equipment lease related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Asset-backed securities Other asset-backed securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	38	49
Fair value on a recurring basis | Level 1 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 1 | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		0
Fair value on a recurring basis | Level 1 | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	1	2
Fair value on a recurring basis | Level 2 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	229	75
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	36	103
Fair value on a recurring basis | Level 2 | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet		1
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	4
Fair value on a recurring basis | Level 2 | Interest rate swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	27	8
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	3	7
Fair value on a recurring basis | Level 2 | U.S. government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	108	234
Fair value on a recurring basis | Level 2 | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	95	125
Fair value on a recurring basis | Level 2 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	619	781
Fair value on a recurring basis | Level 2 | Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	41	40
Fair value on a recurring basis | Level 2 | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		60
Fair value on a recurring basis | Level 2 | Asset-backed securities Automobile loan related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	282	585
Fair value on a recurring basis | Level 2 | Asset-backed securities Credit card related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	162	180
Fair value on a recurring basis | Level 2 | Asset-backed securities Equipment lease related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	48	67
Fair value on a recurring basis | Level 2 | Asset-backed securities Other asset-backed securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	46	75
Fair value on a recurring basis | Level 2 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 2 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	2
Fair value on a recurring basis | Level 2 | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		0
Fair value on a recurring basis | Level 2 | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	0	0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0	0
Fair value on a recurring basis | Level 3 | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet		0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0
Fair value on a recurring basis | Level 3 | Interest rate swap contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	0	0
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	0	0
Fair value on a recurring basis | Level 3 | U.S. government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		0
Fair value on a recurring basis | Level 3 | Asset-backed securities Automobile loan related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Asset-backed securities Credit card related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Asset-backed securities Equipment lease related
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | Asset-backed securities Other asset-backed securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	0	0
Fair value on a recurring basis | Level 3 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	15	0
Fair value on a recurring basis | Level 3 | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities		11
Fair value on a recurring basis | Level 3 | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 0	$ 0