Annual report pursuant to Section 13 and 15(d)

CASH AND INVESTMENTS - Additional Information (Detail)

v3.10.0.1
CASH AND INVESTMENTS - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Gain (Loss) on Securities [Line Items]      
Marketable securities pledged as collateral $ 587,000,000 $ 579,000,000  
Debt Securities, Trading, and Equity Securities, FV-NI 139,000,000 168,000,000  
Gross realized gains on sales of marketable securities     $ 1,000,000
Gross realized losses on sales of marketable securities 4,000,000 2,000,000 1,000,000
Impairment charge 0 0 $ 0
Investments and Restricted Cash 170,000,000 483,000,000  
Variable Life Insurance Policy [Member]      
Gain (Loss) on Securities [Line Items]      
Investments and Restricted Cash 19,000,000    
cash held in escrow [Member]      
Gain (Loss) on Securities [Line Items]      
Restricted Cash and Cash Equivalents, Noncurrent $ 9,000,000 $ 15,000,000  
Measurement Input, Discount Rate [Member]      
Gain (Loss) on Securities [Line Items]      
Weighted average discount rate 8.16% 7.56%