CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Comprehensive income:
Net earnings	$ 582	$ 1,027	$ 506
Other comprehensive income (loss):
Foreign currency translation adjustments	32	25	(97)
Changes in unamortized prior service cost, net of tax benefit of $2 in 2017, $0 in 2016 and $1 in 2015	(5)	(4)	(4)
Unrealized gains on available-for-sale securities	2	1	0
Changes in unamortized net pension and other postretirement benefit gain (loss), net of tax expense (benefit) of ($2) in 2017, ($151) in 2016, and $131 in 2015	(132)	(269)	282
Total comprehensive income	$ 479	$ 780	$ 687