Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities
Net earnings	$ 868	$ 863
Adjustments to reconcile to net cash used in operating activities:
Depreciation and amortization	297	302
Stock-based compensation	18	26
Deferred income taxes	156	33
Changes in assets and liabilities:
Accounts receivable, net	(810)	(718)
Unbilled receivables, net	(584)	(759)
Inventoried costs, net	(2)	(124)
Prepaid expenses and other assets	56	(23)
Accounts payable and other liabilities	(833)	(480)
Income taxes payable, net	10	140
Retiree benefits	(237)	(142)
Other, net	68	(31)
Net cash used in operating activities	(993)	(913)
Investing activities
Capital expenditures	(272)	(284)
Other, net	2	4
Net cash used in investing activities	(270)	(280)
Financing activities
Net proceeds from issuance of long-term debt	2,239	0
Payments to credit facilities	(7)	(20)
Net borrowings on commercial paper	744	814
Common stock repurchases	(344)	(60)
Cash dividends paid	(227)	(211)
Payments of employee taxes withheld from share-based awards	(63)	(61)
Other, net	(46)	0
Net cash provided by financing activities	2,296	462
Increase (decrease) in cash and cash equivalents	1,033	(731)
Cash and cash equivalents, beginning of year	2,245	1,579
Cash and cash equivalents, end of period	$ 3,278	$ 848