Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 319	$ 488	$ 2,342	$ 1,399
Other comprehensive income (loss), net of tax:
Cumulative translation adjustments	(10)	(3)	(8)	(17)
Amortization of net actuarial loss	14	15	41	45
Total other comprehensive income, net of tax	4	12	33	28
Total comprehensive income	$ 323	$ 500	$ 2,375	$ 1,427