Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 6,230	$ 5,046	$ 1,963
Postretirement benefit plans
Net other comprehensive loss recognized during the period, net of tax benefit of $586 million in 2019, $136 million in 2018 and $375 million in 2017	(2,182)	(501)	(1,380)
Amounts reclassified from accumulated other comprehensive loss, net of tax expense of $247 million in 2019, $327 million in 2018 and $437 million in 2017	908	1,202	802
Other, net	41	(75)	141
Other comprehensive income (loss), net of tax	(1,233)	626	(437)
Comprehensive income	$ 4,997	$ 5,672	$ 1,526