v3.20.2
Accumulated Other Comprehensive Income​ (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Apr. 01, 2020
AOCI Attributable to Parent [Abstract]          
Balance at beginning of period $ 1,626 $ 2,821 $ 2,728 $ 2,677  
Separation-related adjustments (A) 314   314    
Other comprehensive income:          
Foreign currency translation 5 (43) 5 14  
Total Other comprehensive income, net of tax 34 (43) 59 14  
Balance at end of period 1,160 2,837 1,160 2,837  
Pension and other postretirement benefits          
AOCI Attributable to Parent [Abstract]          
Balance at beginning of period (1,770) (32) (43) (32)  
Establishment of additional defined benefit plans         $ (1,752)
Separation-related adjustments (A) (50) 0 (50) 0  
Other comprehensive income:          
Other Comprehensive Income (Loss), before Reclassifications, before Tax (40) (1) (38) (2)  
Other Comprehensive Income (Loss) before Reclassifications, Tax 10 1 9 1  
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax (30) 0 (29) (1)  
Amortization of net actuarial loss and prior service cost 86 1 117 2  
Tax expense (20) (1) (27) (1)  
Total amount reclassified from Accumulated other comprehensive loss, net of tax 66 0 90 1  
Total Other comprehensive income, net of tax 36 0 61 0  
Balance at end of period (1,784) (32) (1,784) (32)  
Foreign currency translation          
AOCI Attributable to Parent [Abstract]          
Balance at beginning of period 338 339 338 282  
Separation-related adjustments (A) (396) 0 (396) 0  
Other comprehensive income:          
Foreign currency translation 5 (43) (17) 14  
Net amount reclassified to earnings from Accumulated other comprehensive income 0 0 22 0  
Total Other comprehensive income, net of tax 5 (43) 5 14  
Balance at end of period (53) 296 (53) 296  
Cash flow hedges          
AOCI Attributable to Parent [Abstract]          
Balance at beginning of period 0 0 0 0  
Separation-related adjustments (A) (4) 0 (4) 0  
Other comprehensive income:          
Other Comprehensive Income (Loss), before Reclassifications, before Tax 2 0 2 0  
Other Comprehensive Income (Loss) before Reclassifications, Tax 0 0 0 0  
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 2 0 2 0  
Amortization of net actuarial loss and prior service cost (11) 0 (11) 0  
Tax expense 2 0 2 0  
Total amount reclassified from Accumulated other comprehensive loss, net of tax (9) 0 (9) 0  
Total Other comprehensive income, net of tax (7) 0 (7) 0  
Balance at end of period (11) 0 (11) 0  
Accumulated other comprehensive income (loss)          
AOCI Attributable to Parent [Abstract]          
Balance at beginning of period (1,432) 307 295 250  
Separation-related adjustments (A) (450)   (450)    
Other comprehensive income:          
Total Other comprehensive income, net of tax 34 (43) 59 14  
Balance at end of period $ (1,848) $ 264 $ (1,848) $ 264