Annual report pursuant to Section 13 and 15(d)

CASH AND INVESTMENTS - Age of Gross Unrealized Losses and Fair Value by Investment Category (Detail)

v3.3.1.900
CASH AND INVESTMENTS - Age of Gross Unrealized Losses and Fair Value by Investment Category (Detail)
$ in Millions
 12 Months Ended
Dec. 31, 2015
USD ($)
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value $ 357
Less Than 12 Months Unrealized Losses 6
12 Months or More Fair Value 78
12 Months or More Unrealized Losses 2
Total Fair Value 435
Total Unrealized Losses 8
U.S. government and agency debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 168
Less Than 12 Months Unrealized Losses 1
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 168
Total Unrealized Losses 1
Mortgage and asset-backed debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 28
12 Months or More Unrealized Losses 1
Total Fair Value 28
Total Unrealized Losses 1
Corporate debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 50
12 Months or More Unrealized Losses 1
Total Fair Value 50
Total Unrealized Losses 1
U.S. state and local municipal debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 0
Total Unrealized Losses 0
Equity securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 0
Total Unrealized Losses 0
Non-U.S. government debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 0
Total Unrealized Losses 0
Carbon credit investments  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 189
Less Than 12 Months Unrealized Losses 5
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 189
Total Unrealized Losses 5
Other debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 0
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 0
Total Unrealized Losses $ 0