CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 1,028	$ 72	$ 1,709	$ 222
Other comprehensive income (loss):
Foreign currency translation adjustments	15	17	24	(25)
Changes in unamortized actuarial loss, net of tax expense of $38, $8, $45 and $24	121	23	141	67
Changes in unamortized net prior service credit, net of tax expense of $1, $0, $0 and $0	0	1	1	2
Total other comprehensive income	136	41	166	44
Total comprehensive income	$ 1,164	$ 113	$ 1,875	$ 266