Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 268	$ 570	$ 536	$ 684
Balance at end of period	498	402	498	402
Pension and other postretirement benefit plans, tax (less than)	1	0	(8)	28
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(704)	(651)	(624)	(742)
Other comprehensive (loss) income before reclassifications			(66)
Reclassifications from accumulated other comprehensive income (loss) to net earnings			13
Net other comprehensive (loss) income			(53)
Balance at end of period	(677)	$ (684)	(677)	$ (684)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(321)
Other comprehensive (loss) income before reclassifications			(39)
Reclassifications from accumulated other comprehensive income (loss) to net earnings			0
Net other comprehensive (loss) income			(39)
Balance at end of period	(360)		(360)
Pension and Postretirement Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(305)
Other comprehensive (loss) income before reclassifications			(33)
Reclassifications from accumulated other comprehensive income (loss) to net earnings			11
Net other comprehensive (loss) income			(22)
Balance at end of period	(327)		(327)
Pension and other postretirement benefit plans, tax (less than)			2
Unrealized Gain (Loss) on Foreign Forward Exchange Contracts
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			2
Other comprehensive (loss) income before reclassifications			6
Reclassifications from accumulated other comprehensive income (loss) to net earnings			2
Net other comprehensive (loss) income			8
Balance at end of period	$ 10		$ 10