Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 28, 2021	Mar. 29, 2020
Operating activities
Net earnings	$ 1,837	$ 1,717
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation and amortization	336	301
Stock-based compensation	47	42
Severance and restructuring charges	36	0
Changes in assets and liabilities
Receivables, net	(236)	(555)
Contract assets	(1,363)	(1,095)
Inventories	289	80
Accounts payable	1,023	1,894
Contract liabilities	(290)	151
Postretirement benefit plans	(66)	(39)
Income taxes	301	167
Other, net	(166)	(349)
Net cash provided by operating activities	1,748	2,314
Investing activities
Capital expenditures	(281)	(293)
Other, net	112	(2)
Net cash used for investing activities	(169)	(295)
Financing activities
Dividends paid	(739)	(693)
Repurchases of common stock	(1,000)	(756)
Other, net	(67)	(96)
Net cash used for financing activities	(1,806)	(1,545)
Net change in cash and cash equivalents	(227)	474
Cash and cash equivalents at beginning of period	3,160	1,514
Cash and cash equivalents at end of period	$ 2,933	$ 1,988