Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 6,833	$ 6,230	$ 5,046
Postretirement benefit plans
Net other comprehensive loss recognized during the period, net of tax benefit of $292 million in 2020, $586 million in 2019 and $136 million in 2018	(1,067)	(2,182)	(501)
Amounts reclassified from accumulated other comprehensive loss, net of tax expense of $119 million in 2020, $247 million in 2019 and $327 million in 2018	440	908	1,202
Other, net	60	41	(75)
Other comprehensive income (loss), net of tax	(567)	(1,233)	626
Comprehensive income	$ 6,266	$ 4,997	$ 5,672