Acquisition and Divestitures - Additional Information (Detail) - USD ($) $ in Millions				3 Months Ended			9 Months Ended		12 Months Ended
	Aug. 24, 2016	Aug. 16, 2016	Nov. 06, 2015	Sep. 25, 2016	Dec. 31, 2015	Sep. 27, 2015	Sep. 25, 2016	Sep. 27, 2015	Dec. 31, 2015
Acquisitions And Divestitures [Line Items]
Goodwill				$ 10,791	$ 10,695		$ 10,791		$ 10,695
Gain on step acquisition of AWE, net of tax							104
One-time special cash payment received from Abacus		$ 1,800					1,800
Net gain on divestiture of business segment							1,234
Fair value of shares of common stock tendered and retired							2,497
Other unallocated, net				(173)		$ 32	(401)	$ 61
Severance charges					82	82	99	35
Abacus | Term Loan Facilities
Acquisitions And Divestitures [Line Items]
Amount of issued debt		$ 1,840
Information Systems & Global Solutions
Acquisitions And Divestitures [Line Items]
Percentage of reduction in common stock outstanding		3.00%
Net gain on divestiture of business segment		$ 1,200
Fair value of shares of common stock tendered and retired		2,500
Net book value		3,000
Other adjustments		$ 100
Other unallocated, net				17		40	82	133
Information Systems & Global Solutions | Abacus
Acquisitions And Divestitures [Line Items]
Number of common stock exchanged		76,958,918
Information Systems & Global Solutions | Lockheed Martin
Acquisitions And Divestitures [Line Items]
Number of common stock exchanged		9,369,694
Information Systems & Global Solutions | Continuing Operations
Acquisitions And Divestitures [Line Items]
Pension costs				11		17	54	53
Information Systems & Global Solutions | Discontinued Operations
Acquisitions And Divestitures [Line Items]
Severance charges						20	19	20
Information Systems & Global Solutions | Restatement Adjustment
Acquisitions And Divestitures [Line Items]
Corporate overhead costs				(17)		(40)	(82)	(133)
Sikorsky Aircraft Corporation
Acquisitions And Divestitures [Line Items]
Acquisitions of businesses and investments in affiliates			$ 9,000
Cash on hand			2,000
Proceeds from Issuance of Commercial Paper			$ 1,000
Repayment of commercial paper					1,000
Intangible assets weighted-average useful life			15 years
Customer contractual obligations			$ 507
Customer contractual obligations remaining in 2016				30			30
Customer contractual obligations due in 2017				110			110
Customer contractual obligations due in 2018				70			70
Customer contractual obligations due in 2019				70			70
Customer contractual obligations due in 2020				60			60
Customer contractual obligations due in 2021				10			10
Customer contractual obligations due after 2021				57			57
Sales related to customer contractual obligations, to date				100			$ 100
Goodwill			2,853
Net liabilities			2,940
Sikorsky Aircraft Corporation | Three Hundred And Sixty Four Day Revolving Credit Facility And Five Year Revolving Credit Facility
Acquisitions And Divestitures [Line Items]
Proceeds from borrowings under revolving credit facilities			$ 6,000
Sikorsky Aircraft Corporation | November 2015 Notes
Acquisitions And Divestitures [Line Items]
Proceeds from issuance of fixed interest-rate long-term notes					$ 7,000
Sikorsky Aircraft Corporation | Pro Forma Adjustment
Acquisitions And Divestitures [Line Items]
Amortization expense, net of tax expense						40		115
Amortization expense, tax expense						20		60
Interest expense, net of tax expense						45		130
Interest expense, tax expense						$ 20		$ 65
AWE Management Limited
Acquisitions And Divestitures [Line Items]
Ownership interest percentage acquired	18.00%
Sales									1,500
Net earnings									$ 85
Noncontrolling Interest, Ownership Percentage by Parent	51.00%
Net liabilities	$ 32
Business combination, acquisition of less than 100 percent, noncontrolling interest, fair value	107
AWE Management Limited | Other income, net
Acquisitions And Divestitures [Line Items]
Gain on step acquisition of AWE, net of tax				104
Pre tax gain on step acquisition of AWE				127
Tax on gain on step acquisition of AWE				$ 23
AWE Management Limited | Customer relationships
Acquisitions And Divestitures [Line Items]
Intangible assets	$ 243
Acquired finite-lived intangible assets are amortized	8 years