Fair Value of Financial Assets and Liabilities - Fair Value Hierarchy For Financial Assets And Liabilities Measured At Fair Value (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	$ 14,655,000,000	$ 17,588,000,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(37,000,000)	(35,000,000)
Cash
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,022,000,000	1,725,000,000
Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	4,321,000,000	6,166,000,000
U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	1,951,000,000	3,727,000,000
U.S. corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	1,995,000,000	2,266,000,000
High yield corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	563,000,000	531,000,000
Asset-backed securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	53,000,000
Municipal obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	950,000,000	863,000,000
Commodity derivative assets
Fair Value of Financial Assets and Liabilities [Line Items]
Commodity derivative assets	(12,000,000)
Derivative Asset		4,000,000
Auction rate securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	27,000,000	60,000,000
Foreign debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,564,000,000	2,155,000,000
Publicly traded equity securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	209,000,000	95,000,000
Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	333,000,000	379,000,000
Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	(5,544,000,000)	(5,419,000,000)
Foreign exchange derivative assets/liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	44,000,000	31,000,000
Commodity derivative assets	(71,000,000)	(20,000,000)
Level 1
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	7,082,000,000	9,291,000,000
Level 1 | Cash
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,022,000,000	1,725,000,000
Level 1 | Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	3,710,000,000	5,674,000,000
Level 1 | U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	1,141,000,000	1,797,000,000
Level 1 | Publicly traded equity securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	209,000,000	95,000,000
Level 1 | Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	0	0
Level 2
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	7,546,000,000	8,237,000,000
Level 2 | Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	611,000,000	492,000,000
Level 2 | U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	810,000,000	1,930,000,000
Level 2 | U.S. corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	1,995,000,000	2,266,000,000
Level 2 | High yield corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	563,000,000	531,000,000
Level 2 | Asset-backed securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	53,000,000
Level 2 | Municipal obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	950,000,000	863,000,000
Level 2 | Commodity derivative assets
Fair Value of Financial Assets and Liabilities [Line Items]
Derivative Asset	12,000,000	4,000,000
Level 2 | Foreign debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,564,000,000	2,155,000,000
Level 2 | Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	(5,544,000,000)	(5,419,000,000)
Level 2 | Foreign exchange derivative assets/liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	44,000,000	31,000,000
Commodity derivative assets	(71,000,000)	(20,000,000)
Level 3
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	27,000,000	60,000,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(37,000,000)	(35,000,000)
Level 3 | Auction rate securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	27,000,000	60,000,000
Level 3 | Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	333,000,000	379,000,000
Level 3 | Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	$ 0	$ 0