Annual report pursuant to Section 13 and 15(d)

CASH AND INVESTMENTS - Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Detail)

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CASH AND INVESTMENTS - Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Detail) - USD ($)
$ in Millions
Dec. 31, 2016
Dec. 31, 2015
Cost    
Marketable Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis $ 463  
Due after one year through three years 450  
Due after three years through five years 16  
Marketable Securities, Debt Maturities, After Five Years, Amortized Cost Basis 72  
Marketable Securities, Debt Maturities, Amortized Cost, Total 1,001  
Equity securities 82  
Marketable Securities, Amortized Cost, Total 1,083 $ 1,994
Estimated Fair Value    
Due in one year or less 462  
Due after one year through three years 449  
Due after three years through five years 16  
Due after five years 72  
Marketable Securities, Debt Maturities, Fair Value, Total 999  
Equity securities 92  
Marketable securities 1,091 1,996
Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 1,122 2,047
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 420 710
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 689 1,305
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 13 32
Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 1,091 1,996
Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 402 691
Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 689 1,305
Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Other Long-term Investments | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 31 51
Other Long-term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 18 19
Other Long-term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Other Long-term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 13 32
U.S. government and agency debt securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 312 340
U.S. government and agency debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 312 340
U.S. government and agency debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
U.S. government and agency debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Mortgage and asset-backed debt securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 91 74
Mortgage and asset-backed debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Mortgage and asset-backed debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 91 74
Mortgage and asset-backed debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Corporate debt securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 593 861
Corporate debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Corporate debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 593 861
Corporate debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
U.S. state and local municipal debt securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure   2
U.S. state and local municipal debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure   0
U.S. state and local municipal debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure   2
U.S. state and local municipal debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure   0
Equity securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 2 2
Equity securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Equity securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 2 2
Equity securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Non-U.S. government debt securities | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 3 366
Non-U.S. government debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Non-U.S. government debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 3 366
Non-U.S. government debt securities | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Carbon credit investments | Marketable securities | Fair Value, Measurements, Recurring    
Estimated Fair Value    
Investments, Fair Value Disclosure 90 351
Carbon credit investments | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1    
Estimated Fair Value    
Investments, Fair Value Disclosure 90 351
Carbon credit investments | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2    
Estimated Fair Value    
Investments, Fair Value Disclosure 0 0
Carbon credit investments | Marketable securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3    
Estimated Fair Value    
Investments, Fair Value Disclosure $ 0 $ 0