Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net earnings	$ 6,833	$ 6,230	$ 5,046
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation and amortization	1,290	1,189	1,161
Stock-based compensation	221	189	173
Equity method investment impairment	128	0	0
Tax resolution related to former IS&GS business	55	0	0
Deferred income taxes	5	222	(244)
Severance charges	27	0	96
Gain on property sale	0	(51)	0
Changes in assets and liabilities
Receivables, net	359	107	(179)
Contract assets	(451)	378	(1,480)
Inventories	74	(622)	(119)
Accounts payable	(372)	(1,098)	914
Contract liabilities	491	563	(537)
Postretirement benefit plans	(1,197)	81	(3,574)
Income taxes	(19)	(151)	1,077
Other, net	739	274	804
Net cash provided by operating activities	8,183	7,311	3,138
Investing activities
Capital expenditures	(1,766)	(1,484)	(1,278)
Acquisitions of businesses	(282)	0	0
Other, net	38	243	203
Net cash used for investing activities	(2,010)	(1,241)	(1,075)
Financing activities
Repurchases of common stock	(1,100)	(1,200)	(1,492)
Dividends paid	(2,764)	(2,556)	(2,347)
Proceeds from issuance of commercial paper, net	0	0	600
Repayment of commercial paper, net	0	(600)	0
Repayments of current and long-term debt	(1,650)	(900)	(750)
Issuance of long-term debt, net of related costs	1,131	0	0
Other, net	(144)	(72)	(163)
Net cash used for financing activities	(4,527)	(5,328)	(4,152)
Net change in cash and cash equivalents	1,646	742	(2,089)
Cash and cash equivalents at beginning of year	1,514	772	2,861
Cash and cash equivalents at end of year	$ 3,160	$ 1,514	$ 772