Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 5,046	$ 1,963	$ 5,173
Postretirement benefit plans
Net other comprehensive loss recognized during the period, net of tax benefit of $136 million in 2018, $375 million in 2017 and $668 million in 2016	(501)	(1,380)	(1,232)
Amounts reclassified from accumulated other comprehensive loss, net of tax expense of $327 million in 2018, $437 million in 2017 and $382 million in 2016	1,202	802	699
Reclassifications from divestiture of IS&GS business	0	0	(134)
Other, net	(75)	141	9
Other comprehensive income (loss), net of tax	626	(437)	(658)
Comprehensive income	$ 5,672	$ 1,526	$ 4,515