(Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at beginning of period $ (4,500) $ (4,633)  
Balance at end of period (4,739) (4,500) $ (4,633)
Defined Benefit Pension and Postretirement Adjustments      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at beginning of period (1,916) (2,527) (3,072)
Other comprehensive income (loss) before reclassifications 2 22 59
Reclassification of stranded tax effects (527) 0 0
Amounts reclassified from accumulated other comprehensive income 164 589 486
Balance at end of period (2,277) (1,916) (2,527)
Change in Cumulative Foreign Currency Translation Adjustments      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at beginning of period (2,581) (2,111) (2,287)
Other comprehensive income (loss) before reclassifications 14 (475) 178
Amounts reclassified from accumulated other comprehensive income 102 2 (1)
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interest 0 3 (1)
Balance at end of period (2,465) (2,581) (2,111)
Net Gains and Losses on Cash Flow Hedging Derivatives      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at beginning of period (3) 5 (3)
Other comprehensive income (loss) before reclassifications 4 (10) 15
Reclassification of stranded tax effects (2) 0 0
Amounts reclassified from accumulated other comprehensive income 4 2 (7)
Balance at end of period 3 (3) 5
Reclassification out of Accumulated Other Comprehensive Income [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Amounts reclassified from accumulated other comprehensive income $ 259 $ (593) $ (478)