Quarterly report pursuant to Section 13 or 15(d)

STOCK-BASED COMPENSATION - Additional Information (Detail)

v3.21.2
STOCK-BASED COMPENSATION - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Mar. 25, 2021
Feb. 10, 2021
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Mar. 22, 2021
Stockholders Equity Note [Line Items]                
Stock compensation expense     $ 179 $ 140 $ 700 $ 508    
Impairment charges on property plant and equipment     0 0 30 0    
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]                
Stockholders Equity Note [Line Items]                
Reclassification to earnings, tax effect     0 0 0 (1)    
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]                
Stockholders Equity Note [Line Items]                
Net actuarial gain (loss) resulting from remeasurements of plan assets and liabilities (net of tax effect of $2,039 and $0)         6,470 0    
Reclassification to earnings (net of tax effect of $9 and $13)     $ 29 $ 43 2,421 (130)    
Net actuarial gain (loss) resulting from remeasurements of plan assets and liabilities, tax effect         $ 2,039 $ 0    
Management Incentive Award                
Stockholders Equity Note [Line Items]                
Closing New York Stock Exchange price   $ 165.66           $ 161.06
Long-Term Incentive Performance Award                
Stockholders Equity Note [Line Items]                
Award vesting period         3 years      
Weighted-average fair value of options granted (usd per share)         $ 167.31   $ 92.77  
Long-Term Incentive Performance Award | Restricted Units | Year 2020                
Stockholders Equity Note [Line Items]                
Weighted-average fair value of options granted (usd per share) $ 167.66              
Long-Term Incentive Performance Award | Restricted Units | Year 2021                
Stockholders Equity Note [Line Items]                
Weighted-average fair value of options granted (usd per share) $ 166.52              
Nonqualified Stock Options                
Stockholders Equity Note [Line Items]                
Award vesting period         5 years      
Percentage of the award vesting at each anniversary date of the grant         20.00%      
Expiration period (in years)         10 years      
Stock options granted     200,000          
Weighted-average fair value of options granted (usd per share)   $ 165.66