Annual report pursuant to Section 13 and 15(d)

COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Fair Value Measurement of Plan Assets Using Unobservable Inputs (Detail)

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COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Fair Value Measurement of Plan Assets Using Unobservable Inputs (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year $ 0  
Actual Return on Assets:    
Fair value of plan assets at end of year 8 $ 0
Fair Value, Inputs, Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 11,043  
Actual Return on Assets:    
Fair value of plan assets at end of year 12,926 11,043
Fair Value, Inputs, Level 3 | Corporate Bonds    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 0 6
Actual Return on Assets:    
Assets Held at End of Year 0 0
Assets Sold During the Year 0 0
Purchases 9 0
Sales (1) (6)
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 8 0
Fair Value, Inputs, Level 3 | Hedge Funds    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 0 49
Actual Return on Assets:    
Assets Held at End of Year 0 0
Assets Sold During the Year 0 (49)
Purchases 0 0
Sales 0 0
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 0 0
Fair Value, Inputs, Level 3 | Structured Products    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 0 55
Actual Return on Assets:    
Assets Held at End of Year 0 0
Assets Sold During the Year 0 (49)
Purchases 9 0
Sales (1) (6)
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year $ 8 $ 0