Fair Value Measurement of Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative assets	$ 97	$ 84
Derivative liabilities	$ 5
Foreign Exchange Contract
Fair Value Disclosure, additional details
Derivative lower range (in months)	1 month
Derivative higher range (in years)	1 year
Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	$ 4,299	3,730
Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,552
Fair Value Disclosure, additional details
Cost and equity method investments included in long-term investments	124	184
Corporate debt securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,287	2,519
Corporate debt securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,319
Equity instruments | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	$ 929	1,037
Cash Flow Hedging | Designated as Hedging Instrument | Foreign Exchange Contract
Fair Value Disclosure, additional details
Derivative higher range (in years)	18 months
Cash Flow Hedging | Designated as Hedging Instrument | Other Current Assets | Foreign Exchange Contract
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative assets	$ 42	42
Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,832	4,105
Total financial assets	9,495	13,471
Fair Value, Measurements, Recurring | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	4,299	3,730
Fair Value, Measurements, Recurring | Other Current Assets
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative assets	97	84
Fair Value, Measurements, Recurring | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,552
Fair Value, Measurements, Recurring | Other Current Liabilities
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative liabilities	25	20
Fair Value, Measurements, Recurring | Restricted cash | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	28	19
Fair Value, Measurements, Recurring | Corporate debt securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,287	2,519
Fair Value, Measurements, Recurring | Corporate debt securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,319
Fair Value, Measurements, Recurring | Government and agency securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	55	3
Fair Value, Measurements, Recurring | Government and agency securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		233
Fair Value, Measurements, Recurring | Time deposits | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		152
Fair Value, Measurements, Recurring | Equity instruments | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	929	1,037
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,664	1,694
Total financial assets	2,621	2,750
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	957	1,056
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Current Assets
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative assets	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Current Liabilities
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative liabilities	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Restricted cash | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	28	19
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government and agency securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government and agency securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Time deposits | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity instruments | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	929	1,037
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Cash and cash equivalents	168	2,411
Total financial assets	6,874	10,721
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,342	2,674
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Other Current Assets
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative assets	97	84
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,552
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Other Current Liabilities
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative liabilities	25	20
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Restricted cash | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate debt securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,287	2,519
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate debt securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	3,267	5,319
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Government and agency securities | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	55	3
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Government and agency securities | Long-term Investment
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		233
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Time deposits | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments		152
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Equity instruments | Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments	$ 0	$ 0