v3.20.1
Accumulated Other Comprehensive Income​ (Details) - USD ($)
$ in Millions
 3 Months Ended
Jan. 01, 2020
Mar. 31, 2020
Mar. 31, 2019
AOCI Attributable to Parent [Abstract]      
Balance at beginning of period $ 2,728 $ 2,728 $ 2,677
Establishment of defined benefit plans 1,752    
Other comprehensive income:      
Foreign currency translation   0 57
Total Other comprehensive income, net of tax   25 57
Balance at end of period   1,626 2,821
Pension and other postretirement benefits      
AOCI Attributable to Parent [Abstract]      
Balance at beginning of period (43) (43) (32)
Establishment of defined benefit plans   (1,752) 0
Other comprehensive income:      
Unrecognized net actuarial loss and prior service cost/benefit   2 (1)
Tax expense   (1) 0
Total Other comprehensive income (loss) before reclassifications, net of tax   1 (1)
Amortization of net actuarial loss and prior service cost   31 1
Tax expense   (7) 0
Total amount reclassified from Accumulated other comprehensive loss, net of tax   24 1
Total Other comprehensive income, net of tax   25 0
Balance at end of period   (1,770) (32)
Foreign currency translation      
AOCI Attributable to Parent [Abstract]      
Balance at beginning of period 338 338 282
Other comprehensive income:      
Foreign currency translation   (22) 57
Net amount reclassified to earnings from Accumulated other comprehensive income   22 0
Total Other comprehensive income, net of tax   0 57
Balance at end of period   338 339
Accumulated other comprehensive income (loss)      
AOCI Attributable to Parent [Abstract]      
Balance at beginning of period $ 295 295 250
Other comprehensive income:      
Total Other comprehensive income, net of tax   25 57
Balance at end of period   $ (1,432) $ 307