Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net earnings	$ 3,229	$ 2,869	$ 2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	800	475	456
Mark-to-market pension and OPEB Benefit	655	(536)	950
Stock-based compensation	86	94	93
Deferred income taxes	234	985	(60)
Changes in assets and liabilities:
Accounts receivable, net	202	(209)	46
Unbilled receivables, net	(297)	(422)	(211)
Inventoried costs, net	(37)	25	(53)
Prepaid expenses and other assets	(56)	(92)	(117)
Accounts payable and other liabilities	381	570	18
Income taxes payable, net	(258)	(157)	148
Retiree benefits	(1,083)	(946)	(375)
Other, net	(29)	(43)	(125)
Net cash provided by operating activities	3,827	2,613	2,813
Investing activities
Acquisition of Orbital ATK, net of cash acquired	(7,657)	0	0
Capital expenditures	(1,249)	(928)	(920)
Other investing activities, net	28	39	115
Net cash used in investing activities	(8,878)	(889)	(805)
Financing activities
Payments of long-term debt	(2,276)	0	(321)
Net proceeds from issuance of long-term debt	0	8,245	749
Net (payments to) proceeds from credit facilities	(320)	(13)	135
Net borrowings on commercial paper	198	0	0
Common stock repurchases	(1,263)	(393)	(1,547)
Cash dividends paid	(821)	(689)	(640)
Payments of employee taxes withheld from share-based awards	(85)	(92)	(153)
Other financing activities, net	(28)	(98)	(9)
Net cash provided by (used in) financing activities	(4,595)	6,960	(1,786)
(Decrease) increase in cash and cash equivalents	(9,646)	8,684	222
Cash and cash equivalents, beginning of year	11,225	2,541	2,319
Cash and cash equivalents, end of year	$ 1,579	$ 11,225	$ 2,541