CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net earnings (loss)	$ 150	$ (289)
Other comprehensive income (loss):
Foreign currency translation adjustments	(42)	14
Changes in unamortized actuarial loss, net of tax expense of $16 and $111	44	344
Changes in unamortized net prior service credit, net of tax expense of $0 and $0	1	0
Total other comprehensive income	3	358
Total comprehensive income	$ 153	$ 69