Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities
Net earnings	$ 2,572	$ 1,848
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	534	323
Stock-based compensation	82	66
Deferred income taxes	176	86
Changes in assets and liabilities:
Accounts receivable, net	(52)	(368)
Unbilled receivables, net	(898)	(1,049)
Inventoried costs, net	(102)	(20)
Prepaid expenses and other assets	(109)	(95)
Accounts payable and other liabilities	(125)	80
Income taxes payable, net	(114)	(58)
Retiree benefits	(447)	235
Other, net	(67)	(42)
Net cash provided by operating activities	1,450	1,006
Investing activities
Acquisition of Orbital ATK, net of cash acquired	(7,657)	0
Capital expenditures	(786)	(650)
Other, net	23	21
Net cash used in investing activities	(8,420)	(629)
Financing activities
Payments of long-term debt	(2,276)	0
Payments to credit facilities	(314)	0
Net borrowings on commercial paper	499	0
Common stock repurchases	(209)	(393)
Cash dividends paid	(616)	(515)
Payments of employee taxes withheld from share-based awards	(84)	(91)
Other, net	(27)	(41)
Net cash used in financing activities	(3,027)	(1,040)
Decrease in cash and cash equivalents	(9,997)	(663)
Cash and cash equivalents, beginning of year	11,225	2,541
Cash and cash equivalents, end of period	$ 1,228	$ 1,878