Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	$ 766	$ 701	$ 243
Ending Balance	684	766	701
Pension and other postretirement benefit plans, tax	(9)	11	10
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(649)	(773)	(600)
Other comprehensive loss before reclassifications	(121)
Reclassifications from accumulated other comprehensive loss to net earnings	18
Net other comprehensive (loss) income	(103)
Ending Balance	(742)	(649)	(773)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(239)
Other comprehensive loss before reclassifications	(100)
Reclassifications from accumulated other comprehensive loss to net earnings	0
Net other comprehensive (loss) income	(100)
Ending Balance	(339)	(239)
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(402)
Other comprehensive loss before reclassifications	(19)
Reclassifications from accumulated other comprehensive loss to net earnings	14
Net other comprehensive (loss) income	(5)
Ending Balance	(407)	(402)
Pension and other postretirement benefit plans, tax	9
Unrealized Gain (Loss) on Forward Exchange Contracts
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	2	2	(1)
Other comprehensive loss before reclassifications	(2)	9	7
Reclassifications from accumulated other comprehensive loss to net earnings	4	(9)	(4)
Net other comprehensive (loss) income	2
Ending Balance	4	2	$ 2
Unrealized Loss on Investment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(10)
Other comprehensive loss before reclassifications	0
Reclassifications from accumulated other comprehensive loss to net earnings	0
Net other comprehensive (loss) income	0
Ending Balance	$ 0	$ (10)
Accounting Standards Update 2016-01 | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Amounts reclassified to retained income				$ 10
Accounting Standards Update 2016-01 | Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Amounts reclassified to retained income				0
Accounting Standards Update 2016-01 | Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Amounts reclassified to retained income				0
Accounting Standards Update 2016-01 | Unrealized Gain (Loss) on Forward Exchange Contracts
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Amounts reclassified to retained income				0
Accounting Standards Update 2016-01 | Unrealized Loss on Investment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Amounts reclassified to retained income				$ 10