Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities
Net earnings	$ 2,200	$ 1,990	$ 2,069
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	456	467	462
Stock-based compensation	93	99	134
Excess tax benefits from stock-based compensation	0	(103)	(81)
Deferred income taxes	36	572	216
Changes in assets and liabilities:
Accounts receivable, net	(461)	(30)	(105)
Inventoried costs, net	(15)	(80)	(24)
Prepaid expenses and other assets	(110)	43	13
Accounts payable and other liabilities	198	(632)	(89)
Income taxes payable	148	135	84
Retiree benefits	393	(263)	(17)
Other, net	(125)	(36)	(69)
Net cash provided by operating activities	2,813	2,162	2,593
Investing activities
Capital expenditures	(920)	(471)	(561)
Other investing activities, net	115	40	(84)
Net cash used in investing activities	(805)	(431)	(645)
Financing activities
Common stock repurchases	(1,547)	(3,182)	(2,668)
Net proceeds from issuance of long-term debt	749	600	0
Payments of long-term debt	(321)	0	0
Cash dividends paid	(640)	(603)	(563)
Payments of employee taxes withheld from share-based awards	(153)	(186)	(127)
Net proceeds from credit facilities	135	0	0
Other financing activities, net	(9)	96	123
Net cash used in financing activities	(1,786)	(3,275)	(3,235)
(Decrease) increase in cash and cash equivalents	222	(1,544)	(1,287)
Cash and cash equivalents, beginning of year	2,319	3,863	5,150
Cash and cash equivalents, end of year	$ 2,541	$ 2,319	$ 3,863