Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
CASH AND INVESTMENTS - Age of Gross Unrealized Losses and Fair Value by Investment Category (Detail)
$ in Millions
 12 Months Ended
Dec. 31, 2017
USD ($)
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value $ 328
Less Than 12 Months Unrealized Losses 3
12 Months or More Fair Value 185
12 Months or More Unrealized Losses 1
Total Fair Value 513
Total Unrealized Losses 4
U.S. government and agency debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 183
Less Than 12 Months Unrealized Losses 2
12 Months or More Fair Value 90
12 Months or More Unrealized Losses 1
Total Fair Value 273
Total Unrealized Losses 3
Mortgage and asset-backed debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 36
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 25
12 Months or More Unrealized Losses 0
Total Fair Value 61
Total Unrealized Losses 0
Corporate debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 101
Less Than 12 Months Unrealized Losses 1
12 Months or More Fair Value 70
12 Months or More Unrealized Losses 0
Total Fair Value 171
Total Unrealized Losses 1
Non-U.S. government debt securities  
Gain (Loss) on Investments [Line Items]  
Less Than 12 Months Fair Value 8
Less Than 12 Months Unrealized Losses 0
12 Months or More Fair Value 0
12 Months or More Unrealized Losses 0
Total Fair Value 8
Total Unrealized Losses $ 0