Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities
Net earnings	$ 5,302	$ 3,605	$ 3,614
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation and amortization	1,215	1,026	994
Stock-based compensation	149	138	164
Deferred income taxes	(152)	(445)	(401)
Goodwill impairment charges			119
Severance charges	99	102
Gain on divestiture of IS&GS business	(1,242)
Gain on step acquisition of AWE	(104)
Changes in assets and liabilities
Receivables, net	(811)	(256)	28
Inventories, net	(46)	(398)	77
Accounts payable	(188)	(160)	95
Customer advances and amounts in excess of costs incurred	3	(32)	(572)
Postretirement benefit plans	1,028	1,068	(880)
Income taxes	146	(48)	351
Other, net	(210)	501	277
Net cash provided by operating activities	5,189	5,101	3,866
Investing activities
Capital expenditures	(1,063)	(939)	(845)
Acquisitions of businesses and investments in affiliates		(9,003)	(898)
Other, net	78	208	20
Net cash used for investing activities	(985)	(9,734)	(1,723)
Financing activities
Special cash payment from divestiture of IS&GS business	1,800
Repurchases of common stock	(2,096)	(3,071)	(1,900)
Proceeds from stock option exercises	106	174	308
Dividends paid	(2,048)	(1,932)	(1,760)
Proceeds from the issuance of long-term debt		9,101
Repayments of long-term debt	(952)
Proceeds from borrowings under revolving credit facilities		6,000
Repayments of borrowings under revolving credit facilities		(6,000)
Other, net	(267)	5	38
Net cash (used for) provided by financing activities	(3,457)	4,277	(3,314)
Net change in cash and cash equivalents	747	(356)	(1,171)
Cash and cash equivalents at beginning of year	1,090	1,446	2,617
Cash and cash equivalents at end of year	$ 1,837	$ 1,090	$ 1,446