Fair Value of Financial Assets and Liabilities - Fair Value Hierarchy For Financial Assets And Liabilities Measured At Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	$ 14,783,000	$ 14,655,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(39,000)	(37,000)
Cash
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,095,000	2,022,000
Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	4,454,000	4,321,000
U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,441,000	1,951,000
U.S. corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,248,000	1,995,000
High yield corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	287,000	563,000
Asset-backed securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	20,000	53,000
Municipal obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	732,000	950,000
Commodity derivative liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Commodity derivative liabilities	(4,000)
Derivative Asset		12,000
Auction rate securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	25,000	27,000
Foreign debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,323,000	2,564,000
Publicly traded equity securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	158,000	209,000
Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	384,000	333,000
Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	(4,999,000)	(5,544,000)
Foreign exchange derivative assets/liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	39,000	44,000
Commodity derivative liabilities	(78,000)	(71,000)
Level 1
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	7,609,000	7,082,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Level 1 | Cash
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,095,000	2,022,000
Level 1 | Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	3,861,000	3,710,000
Level 1 | U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	1,495,000	1,141,000
Level 1 | Publicly traded equity securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	158,000	209,000
Level 1 | Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments		0
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	7,149,000	7,546,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Level 2 | Cash equivalents
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	593,000	611,000
Level 2 | U.S. government and agency obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	946,000	810,000
Level 2 | U.S. corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,248,000	1,995,000
Level 2 | High yield corporate debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	287,000	563,000
Level 2 | Asset-backed securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	20,000	53,000
Level 2 | Municipal obligations
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	732,000	950,000
Level 2 | Commodity derivative liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Commodity derivative liabilities	(4,000)
Derivative Asset		12,000
Level 2 | Foreign debt securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	2,323,000	2,564,000
Level 2 | Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments		0
Level 2 | Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	(4,999,000)	(5,544,000)
Level 2 | Foreign exchange derivative assets/liabilities
Fair Value of Financial Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	39,000	44,000
Commodity derivative liabilities	(78,000)	(71,000)
Level 3
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	25,000	27,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(39,000)	(37,000)
Level 3 | Auction rate securities
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	25,000	27,000
Level 3 | Strategic investments carried at cost
Fair Value of Financial Assets and Liabilities [Line Items]
Total cash and investments	384,000	333,000
Level 3 | Long-term Debt
Fair Value of Financial Assets and Liabilities [Line Items]
Debt Instrument, Fair Value Disclosure	$ 0	$ 0