Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	$ 135	$ 77
Asset-backed securities:
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	1,055
Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	4	7
Fair value on a recurring basis | Fair Value | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	107	38
Derivative instruments - liabilities	42	82
Fair value on a recurring basis | Fair Value | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - liabilities	7	5
Fair value on a recurring basis | Fair Value | Interest rate swaps
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	28	39
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	480	309
Fair value on a recurring basis | Fair Value | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	23	55
Fair value on a recurring basis | Fair Value | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	668	472
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	49	29
Fair value on a recurring basis | Fair Value | U.S. dollar commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	30	55
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	718	397
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	268	149
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	64	38
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	5	8
Fair value on a recurring basis | Fair Value | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	34	99
Fair value on a recurring basis | Fair Value | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	14	23
Fair value on a recurring basis | Fair Value | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	4	7
Fair value on a recurring basis | Fair Value | Investments
Assets and Liabilities Measured on Recurring Basis
Investments	4	21
Fair value on a recurring basis | Level 1 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	98	36
Derivative instruments - liabilities	42	82
Fair value on a recurring basis | Level 1 | Commodity price swap contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - liabilities	7	5
Fair value on a recurring basis | Level 1 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	34	99
Fair value on a recurring basis | Level 1 | Investments
Assets and Liabilities Measured on Recurring Basis
Investments	4	21
Fair value on a recurring basis | Level 2 | Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	9	2
Fair value on a recurring basis | Level 2 | Interest rate swaps
Assets and Liabilities Measured on Recurring Basis
Derivative instruments - assets	28	39
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	480	309
Fair value on a recurring basis | Level 2 | Foreign government agency securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	23	55
Fair value on a recurring basis | Level 2 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	668	472
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	49	29
Fair value on a recurring basis | Level 2 | U.S. dollar commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	30	55
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	718	397
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	268	149
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	64	38
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	5	8
Fair value on a recurring basis | Level 2 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	14	23
Fair value on a recurring basis | Level 3 | Auction rate securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 4	$ 7