Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	$ 684	$ 766	$ 701
Ending Balance	536	684	766
Pension and other postretirement benefit plans, tax	39	(9)	11
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(742)	(649)	(773)
Other comprehensive gain (loss) before reclassifications	30
Reclassifications from accumulated other comprehensive loss to net earnings	88
Net other comprehensive gain (loss) income	118
Ending Balance	(624)	(742)	$ (649)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(339)
Other comprehensive gain (loss) before reclassifications	18
Reclassifications from accumulated other comprehensive loss to net earnings	0
Net other comprehensive gain (loss) income	18
Ending Balance	(321)	(339)
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(407)
Other comprehensive gain (loss) before reclassifications	9
Reclassifications from accumulated other comprehensive loss to net earnings	93
Net other comprehensive gain (loss) income	102
Ending Balance	(305)	(407)
Pension and other postretirement benefit plans, tax	(39)
Unrealized Gain (Loss) on Forward Exchange Contracts
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	4
Other comprehensive gain (loss) before reclassifications	3
Reclassifications from accumulated other comprehensive loss to net earnings	(5)
Net other comprehensive gain (loss) income	(2)
Ending Balance	$ 2	$ 4