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, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year $ 40,864  
Actual Return on Assets:    
Fair value of plan assets at end of year 47,767 $ 40,864
Fair Value, Inputs, Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 6  
Actual Return on Assets:    
Fair value of plan assets at end of year 12 6
Fair Value, Inputs, Level 3 | Corporate Bonds    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 2 8
Actual Return on Assets:    
Assets Held at End of Year 0 0
Assets Sold During the Year (4) (7)
Purchases 4 11
Sales (2) (10)
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 0 2
Fair Value, Inputs, Level 3 | Hedge Funds    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 4 0
Actual Return on Assets:    
Assets Held at End of Year 1 0
Assets Sold During the Year 0 0
Purchases 7 9
Sales (5)
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year 12 4
Fair Value, Inputs, Level 3 | Structured Products    
Defined Benefit Plan Disclosure [Line Items]    
Fair value of plan assets at beginning of year 6 8
Actual Return on Assets:    
Assets Held at End of Year 1 0
Assets Sold During the Year (4) (7)
Purchases 11 20
Sales (2) (15)
Transfers Into (Out of) Level 3 0 0
Fair value of plan assets at end of year $ 12 $ 6