Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity [Abstract]
Tax provision of net actuarial loss and prior service cost related to pension and other postretirement benefit plans included in other comprehensive income	$ 5
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	650
Other comprehensive income before reclassifications	122
Reclassifications from accumulated other comprehensive loss to net earnings	2
Net other comprehensive income	124
Ending Balance	711	$ 650
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(773)
Ending Balance	(649)	(773)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(332)
Other comprehensive income before reclassifications	93
Reclassifications from accumulated other comprehensive loss to net earnings	0
Net other comprehensive income	93
Ending Balance	(239)	(332)
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	(443)
Other comprehensive income before reclassifications	30
Reclassifications from accumulated other comprehensive loss to net earnings	11
Net other comprehensive income	41
Ending Balance	(402)	(443)
Unrealized Gain (Loss) on Forward Exchange Contracts
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	2
Other comprehensive income before reclassifications	9	7	$ 0
Reclassifications from accumulated other comprehensive loss to net earnings	(9)	(4)	$ 0
Net other comprehensive income	0
Ending Balance	2	2
Unrealized Loss on Investment
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Beginning Balance	0
Other comprehensive income before reclassifications	(10)
Reclassifications from accumulated other comprehensive loss to net earnings	0
Net other comprehensive income	(10)
Ending Balance	$ (10)	$ 0