v3.20.4
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Line Items]      
Deferred Tax Assets, Operating Loss Carryforwards $ 510 $ 411  
Operating Loss Carryforwards, Valuation Allowance 79 79  
Operating Loss Carryforwards, U. S. Federal 1,000    
Operating Loss Carryforwards, State and Local 1,070    
Operating Loss Carryforwards, Foreign $ 1,060    
Operating Loss Carryforwards, Expiration Dates, U. S. Federal 2021    
Operating Loss Carryforwards, Expiration Dates, State and Local 2021    
State and local tax credit carryforwards $ 20    
Tax credit carryforward, year expiration begins 2021    
State and local tax credit carryforward, year expiration begins 2023    
Valuation Allowance, Deferred Tax Asset, Change in Amount $ 84 222  
Income Tax Examination, Penalties and Interest Accrued 129 198  
Income Tax Examination, Penalties and Interest Expense 41 60 $ 18
U.S. Federal [Member]      
Income Tax Disclosure [Line Items]      
Deferred Tax Assets, Tax Credit Carryforwards, General Business 14    
Deferred Tax Assets, Capital Loss Carryforward 0 $ 0  
Foreign Tax Authority [Member]      
Income Tax Disclosure [Line Items]      
Deferred Tax Assets, Capital Loss Carryforward 258    
Valuation allowance related to capital loss carryforwards $ 258