v3.19.3.a.u2
Income Taxes - Narrative (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Income Tax Contingency [Line Items]      
Undistributed earnings of foreign subsidiaries $ 250    
Unrecognized tax benefits that would impact effective tax rate 68    
Reserve on uncertain tax positions 9,855 $ 1,294  
Deferred tax asset realized, indefinite deferred tax liability used as income 979 920  
Gross increases - current year tax positions 1,566 57 $ 52
Unrecognized tax benefit that would not impact effective tax rate 1,700    
Gross decreases - settlements with tax authorities 143 0 $ 0
Unrecognized tax benefit, income tax penalties and interest accrued 10 $ 17  
Tax Years 2013 and 2014      
Income Tax Contingency [Line Items]      
Gross decreases - settlements with tax authorities 123    
Foreign Tax Authority      
Income Tax Contingency [Line Items]      
Operating loss carryforward, subject to expiration 7,300    
Operating loss carryforward, not subject to expiration 1,000    
Gross increases - current year tax positions 6,400    
Unrecognized tax benefits, decrease from current period tax positions 1,400    
Domestic Tax Authority      
Income Tax Contingency [Line Items]      
Operating loss carryforward, subject to expiration 2,900    
Operating loss carryforward, not subject to expiration 5,900    
Tax credit carry forward, subject to expiration 490    
State and Local Jurisdiction      
Income Tax Contingency [Line Items]      
Operating loss carryforward, subject to expiration 2,600    
Operating loss carryforward, not subject to expiration 77    
Tax credit carry forward, subject to expiration 10    
Tax credit carryforward, not subject to expiration $ 262