Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	$ 79	$ 135
Asset-backed securities:
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	951
Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	5	4
Fair value on a recurring basis | Fair Value | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	52	107
Derivative instruments - liabilities	47	42
Fair value on a recurring basis | Fair Value | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - liabilities	7	7
Fair value on a recurring basis | Fair Value | Interest rate swaps
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	27	28
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	362	480
Fair value on a recurring basis | Fair Value | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	3	23
Fair value on a recurring basis | Fair Value | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	635	668
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	58	49
Fair value on a recurring basis | Fair Value | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	70	30
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	583	718
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	259	268
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	103	64
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	6	5
Fair value on a recurring basis | Fair Value | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	59	34
Fair value on a recurring basis | Fair Value | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	19	14
Fair value on a recurring basis | Fair Value | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	5	4
Fair value on a recurring basis | Fair Value | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	3	4
Fair value on a recurring basis | Level 1 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	47	98
Derivative instruments - liabilities	47	42
Fair value on a recurring basis | Level 1 | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - liabilities	7	7
Fair value on a recurring basis | Level 1 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	59	34
Fair value on a recurring basis | Level 1 | Investments
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	3	4
Fair value on a recurring basis | Level 2 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	5	9
Fair value on a recurring basis | Level 2 | Interest rate swaps
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	27	28
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	362	480
Fair value on a recurring basis | Level 2 | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	3	23
Fair value on a recurring basis | Level 2 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	635	668
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	58	49
Fair value on a recurring basis | Level 2 | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	70	30
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	583	718
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	259	268
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	103	64
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	6	5
Fair value on a recurring basis | Level 2 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	19	14
Fair value on a recurring basis | Level 3 | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 5	$ 4