v3.20.4
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Taxes Disclosure [Line Items]      
Discrete income tax benefit recognized in connection with charitable contribution $ 241    
Income tax expense (benefit) net noncash associated with revaluation of deferred income tax assets and liabilities 79    
Net discrete tax benefits, including benefits related to changes in the Company’s organizational entity structure and stock-based compensation awards $ 139    
Discrete income tax benefit for vested stock awards   $ 28  
Federal statutory tax rate 21.00% 21.00% 21.00%
Deferred tax asset $ 1,028 $ 796  
Deferred income tax liabilities 3,673 3,734  
Deferred tax assets, valuation allowance 26 51  
Income taxes receivable 175 282  
Income taxes payable 131 293  
Unrecognized tax benefits that would affect effective tax rate if recognized 565 513 $ 462
Interest and penalties accrued during period 31 27 30
Liability for interest and penalties 164 133 $ 106
Minimum [Member]      
Income Taxes Disclosure [Line Items]      
Liability for uncertain tax positions 5    
Maximum [Member]      
Income Taxes Disclosure [Line Items]      
Liability for uncertain tax positions 15    
Related to the Same Tax Jurisdiction [Member]      
Income Taxes Disclosure [Line Items]      
Deferred tax asset 304 175  
Deferred income tax liabilities 3,673 3,734  
State and Local Jurisdiction [Member]      
Income Taxes Disclosure [Line Items]      
Net operating loss carryforwards $ 2,000 1,900  
Net operating loss carryforwards, maturity year 2022    
Foreign [Member]      
Income Taxes Disclosure [Line Items]      
Net operating loss carryforwards $ 102 $ 110  
Net operating loss carryforwards, maturity year 2021    
Foreign net loss carry forwards, subject to expiration $ 2