L3 10-Q 2 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 25, 2015	Oct. 23, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 25, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	LLL
Entity Registrant Name	L 3 COMMUNICATIONS HOLDINGS INC
Entity Central Index Key	1,056,239
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		78,387,731

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 323	$ 442
Billed receivables, net of allowances of $13 in 2015 and $14 in 2014	796	852
Contracts in process	2,483	2,295
Inventories	374	288
Deferred income taxes	129	127
Other current assets	190	186
Assets held for sale		547
Total current assets	4,295	4,737
Property, plant and equipment, net	1,108	1,088
Goodwill	7,112	7,501
Identifiable intangible assets	256	243
Deferred debt issue costs	22	27
Other assets	243	240
Total assets	13,036	13,836
Current liabilities:
Accounts payable, trade	490	382
Accrued employment costs	562	510
Accrued expenses	369	402
Advance payments and billings in excess of costs incurred	629	573
Income taxes	18	23
Other current liabilities	396	398
Liabilities held for sale		237
Total current liabilities	2,464	2,525
Pension and postretirement benefits	1,163	1,187
Deferred income taxes	407	443
Other liabilities	403	382
Long-term debt	3,940	3,939
Total liabilities	$ 8,377	$ 8,476
Commitments and contingencies (see Note 17)
L-3 shareholders' equity:
L-3 Communications Holdings, Inc.'s common stock: $.01 par value; 300,000,000 shares authorized, 79,004,449 shares outstanding at September 25, 2015 and 82,040,525 shares outstanding at December 31, 2014 (L-3 Communications Corporation's common stock: $.01 par value, 100 shares authorized, issued and outstanding)	$ 5,985	$ 5,799
L-3 Communications Holdings, Inc.'s treasury stock (at cost), 78,177,799 shares at September 25, 2015 and 73,005,891 shares at December 31, 2014	(6,716)	(6,111)
Retained earnings	5,945	6,181
Accumulated other comprehensive loss	(630)	(584)
Total L-3 shareholders' equity	4,584	5,285
Noncontrolling interests	75	75
Total equity	4,659	5,360
Total liabilities and equity	$ 13,036	$ 13,836

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Allowances for billed receivables	$ 13	$ 14
L-3 Communications Holdings, Inc. [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares outstanding	79,004,449	82,040,525
Treasury stock (at cost), shares	78,177,799	73,005,891
L-3 Communications Corporation [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Net sales:
Products	$ 1,612	$ 1,644	$ 4,761	$ 4,991
Services	1,205	1,296	3,562	3,925
Total net sales	2,817	2,940	8,323	8,916
Cost of sales:
Products	(1,417)	(1,480)	(4,335)	(4,498)
Services	(1,114)	(1,203)	(3,316)	(3,636)
Total cost of sales	(2,531)	(2,683)	(7,651)	(8,134)
Loss related to business divestitures	(9)		(29)
Impairment charge	(491)		(491)
Operating (loss) income	(214)	257	152	782
Interest expense	(47)	(47)	(139)	(129)
Interest and other income, net	3	5	11	14
(Loss) income before income taxes	(258)	215	24	667
Provision for income taxes	(38)	(58)	(87)	(197)
Net (loss) income	(296)	157	(63)	470
Net income attributable to noncontrolling interests	(3)	(3)	(11)	(9)
Net (loss) income attributable to L-3	$ (299)	$ 154	$ (74)	$ 461
(Loss) earnings per share attributable to L-3 Holdings' common shareholders:
Basic	$ (3.74)	$ 1.81	$ (0.91)	$ 5.38
Diluted	(3.74)	1.78	(0.91)	5.21
Cash dividends paid per common share	$ 0.65	$ 0.60	$ 1.95	$ 1.80
L-3 Holdings' weighted average common shares outstanding:
Basic	80	85.1	81.5	85.7
Diluted	80	86.6	81.5	88.4

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Statement of Comprehensive Income [Abstract]
Net (loss) income		$ (296)	$ 157	$ (63)	$ 470
Other comprehensive income (loss):
Foreign currency translation adjustments		(55)	(63)	(84)	(57)
Unrealized losses on hedging instruments	[1]	(7)	(3)	(3)
Pension and postretirement benefit plans:
Amortization of net loss and prior service cost previously recognized	[2]	10	2	32	7
Net gain arising during the period	[3]			9
Total other comprehensive (loss) income		(52)	(64)	(46)	(50)
Comprehensive (loss) income		(348)	93	(109)	420
Comprehensive income attributable to noncontrolling interests		(3)	(3)	(11)	(9)
Comprehensive (loss) income attributable to L-3		$ (351)	$ 90	$ (120)	$ 411
[1]	Amounts are net of income tax benefits of $3 million and $1 million for the quarterly periods ended September 25, 2015 and September 26, 2014, respectively, and income tax benefits of $2 million for the year-to-date period ended September 25, 2015.
[2]	Amounts are net of income taxes of $7 million and $1 million for the quarterly periods ended September 25, 2015 and September 26, 2014, respectively, and income taxes of $18 million and $4 million for the year-to-date periods ended September 25, 2015 and September 26, 2014, respectively.
[3]	Represents the reclassification of actuarial losses into net income related to the Marine Systems International business divestiture in accordance with Accounting Standards Codification 715 Defined Benefit Plans - Pension. Amounts are net of income taxes of $5 million for the year-to-date period ended September 25, 2015.

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Statement of Comprehensive Income [Abstract]
Net of income taxes benefits on unrealized gains on hedging instruments	$ 3	$ 1	$ 2
Income taxes on amortization of net loss and prior service cost previously recognized	$ 7	$ 1	18	$ 4
Income tax expense on net gain arising during the period			$ 5

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2013	$ 6,056	$ 1	$ 5,652	$ (5,288)	$ 5,726	$ (110)	$ 75
Beginning Balance, Shares at Dec. 31, 2013		85.8
Class of Stock [Line Items]
Net (loss) income	470				461		9
Other comprehensive loss	(50)					(50)
Distributions to noncontrolling interests	(8)						(8)
Cash dividends declared on common stock	(159)				(159)
Shares issued:
Employee savings plans	105		105
Employee savings plans, Shares		1
Exercise of stock options	102		102
Exercise of stock options, Shares		1.1
Employee stock purchase plan	18		18
Employee stock purchase plan, Shares		0.3
Vesting of restricted stock units	0	$ 0	0	0	0	0	0
Vesting of restricted stock units, Shares		0.7
Employee restricted stock units surrendered in lieu of income tax withholding	(27)		(27)
Employee restricted stock units surrendered in lieu of income tax withholding, Shares		(0.2)
Stock-based compensation expense	39		39
Treasury stock purchased	(413)			(413)
Treasury stock purchased, Shares		(3.6)
Retirement of Convertible Contingent Debt Securities	(160)		(160)
Other	6		6
Other, Shares
Ending Balance at Sep. 26, 2014	5,979	$ 1	5,735	(5,701)	6,028	(160)	76
Ending Balance, Shares at Sep. 26, 2014		85.1
Beginning Balance at Dec. 31, 2014	5,360	$ 1	5,798	(6,111)	6,181	(584)	75
Beginning Balance, Shares at Dec. 31, 2014		82
Class of Stock [Line Items]
Net (loss) income	(63)				(74)		11
Other comprehensive loss	(46)					(46)
Distributions to noncontrolling interests	(11)						(11)
Cash dividends declared on common stock	(162)				(162)
Shares issued:
Employee savings plans	95		95
Employee savings plans, Shares		0.8
Exercise of stock options	65		65
Exercise of stock options, Shares		0.6
Employee stock purchase plan	17		17
Employee stock purchase plan, Shares		0.3
Vesting of restricted stock units	0	$ 0	0	0	0	0	0
Vesting of restricted stock units, Shares		0.7
Employee restricted stock units surrendered in lieu of income tax withholding	(33)		(33)
Employee restricted stock units surrendered in lieu of income tax withholding, Shares		(0.2)
Stock-based compensation expense	36		36
Treasury stock purchased	(605)			(605)
Treasury stock purchased, Shares		(5.2)
Other	6		6
Other, Shares
Ending Balance at Sep. 25, 2015	$ 4,659	$ 1	$ 5,984	$ (6,716)	$ 5,945	$ (630)	$ 75
Ending Balance, Shares at Sep. 25, 2015		79

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Class of Stock [Line Items]
Cash dividends declared per share	$ 1.95	$ 1.80
Retained Earnings [Member]
Class of Stock [Line Items]
Cash dividends declared per share	$ 1.95	$ 1.80

Condensed Consolidated Stateme9

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Operating activities:
Net (loss) income	$ (63)	$ 470
Depreciation of property, plant and equipment	129	127
Amortization of intangibles and other assets	35	38
Deferred income tax (benefit) provision	(21)	91
Stock-based employee compensation expense	36	39
Excess income tax benefits related to share-based payment arrangements	(24)	(16)
Contributions to employee savings plans in L-3 Holdings' common stock	95	105
Impairment charge	491
Amortization of pension and postretirement benefit plans net loss and prior service cost	50	11
Amortization of bond discounts and deferred debt issue costs (included in interest expense)	6	5
Loss related to business divestitures	29
Other non-cash items	(4)	(5)
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:
Billed receivables	48	118
Contracts in process	(165)	(144)
Inventories	(77)	(11)
Other assets	(13)
Accounts payable, trade	121	(119)
Accrued employment costs	47	26
Accrued expenses	(40)	(57)
Advance payments and billings in excess of costs incurred	2	39
Income taxes		(4)
Other current liabilities	(11)	(40)
Pension and postretirement benefits	(18)	(40)
All other operating activities	(22)	(28)
Net cash from operating activities	631	605
Investing activities:
Business acquisitions, net of cash acquired	(260)	(57)
Proceeds from the sale of businesses, net of closing date cash balances	308
Capital expenditures	(140)	(115)
Dispositions of property, plant and equipment	2	4
Other investing activities	4	6
Net cash used in investing activities	(86)	(162)
Financing activities:
Proceeds from sale of Senior Notes		996
Retirement of CODES		(935)
Borrowings under revolving credit facility	861	1,367
Repayment of borrowings under revolving credit facility	(861)	(1,367)
Common stock repurchased	(605)	(413)
Dividends paid on L-3 Holdings' common stock	(163)	(158)
Proceeds from exercises of stock options	41	87
Proceeds from employee stock purchase plan	26	27
Excess income tax benefits related to share-based payment arrangements	24	16
Debt issue costs		(8)
Employee restricted stock units surrendered in lieu of income tax withholding	(33)	(27)
Other financing activities	(1)	(11)
Net cash used in financing activities	(711)	(426)
Effect of foreign currency exchange rate changes on cash and cash equivalents	(14)	(9)
Change in cash balance in assets held for sale	61
Net (decrease) increase in cash and cash equivalents	(119)	8
Cash and cash equivalents, beginning of the period	442	500
Cash and cash equivalents, end of the period	$ 323	$ 508

Description of Business

Description of Business	9 Months Ended
	Sep. 25, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	1. Description of Business L-3 Communications Holdings, Inc. derives all of its operating income and cash flows from its wholly-owned subsidiary, L-3 Communications Corporation (L-3 Communications). L-3 Communications Holdings, Inc. (L-3 Holdings and, together with its subsidiaries, referred to herein as L-3 or the Company) is a prime contractor in Intelligence, Surveillance and Reconnaissance (ISR) systems, aircraft sustainment (including modifications, logistics and maintenance), simulation and training, night vision and image intensification equipment, enterprise and mission information technology (IT) solutions and cyber operations. L-3 is also a leading provider of a broad range of communication and electronic systems and products used on military and commercial platforms. The Company’s customers include the United States (U.S.) Department of Defense (DoD) and its prime contractors, U.S. Government intelligence agencies, the U.S. Department of Homeland Security (DHS), foreign governments, and domestic and international commercial customers. The Company has the following four reportable segments: (1) Electronic Systems, (2) Aerospace Systems, (3) Communication Systems and (4) National Security Solutions (NSS). Electronic Systems provides a broad range of components, products, subsystems, systems and related services for military and commercial customers in several niche markets across several business areas. These business areas include precision engagement & training, sensor systems, power & propulsion systems, aviation products and security systems, warrior systems and advanced programs. Aerospace Systems delivers integrated solutions for the global ISR market and provides modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. Communication Systems delivers products and services for the global communications market, specializing in strategic and tactical airborne, space, ground and sea-based communication systems. NSS provides cybersecurity solutions, high-performance computing, enterprise IT services, analytics and intelligence analysis to the DoD, U.S. Government intelligence agencies, federal civilian agencies and foreign governments. In April 2015, the Company realigned its Platform and Logistics Solutions sector within its Aerospace Systems segment to enhance the operational effectiveness and competitiveness of its platform systems business. The platform systems business was integrated within the ISR Systems sector and the new integrated organization was renamed the ISR and Aircraft Systems sector. The Logistics Solutions sector remains a separate sector within the Aerospace Systems segment. This realignment did not impact the composition of the Company’s reporting units. Financial information with respect to the Company’s segments is included in Note 21 to the unaudited condensed consolidated financial statements and in Note 22 to the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 25, 2015
Accounting Policies [Abstract]
Basis of Presentation	2. Basis of Presentation These unaudited condensed consolidated financial statements for the quarterly and year-to-date periods ended September 25, 2015 should be read in conjunction with the audited consolidated financial statements of L-3 Principles of Consolidation and Reporting The accompanying financial statements comprise the consolidated financial statements of L-3 Holdings and L-3 Communications. L-3 Holdings’ only asset is its investment in the common stock of L-3 Communications, its wholly-owned subsidiary, and its only obligations are: (1) its guarantee of borrowings under the Amended and Restated Revolving Credit Facility (Credit Facility) of L-3 Communications and (2) its guarantee of other contractual obligations of L-3 Communications and its subsidiaries. All issuances of and conversions into L-3 Holdings’ equity securities, including grants of stock options, restricted stock units and performance units by L-3 Holdings to employees and directors of L-3 Communications and its subsidiaries, have been reflected in the consolidated financial statements of L-3 Communications. As a result, the consolidated financial positions, results of operations and cash flows of L-3 Holdings and L-3 Communications are substantially the same. See Note 23 for additional information regarding the unaudited financial information of L-3 Communications and its subsidiaries. The unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the disclosures required by U.S. GAAP for a complete set of annual audited financial statements. The December 31, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. In the opinion of management, all adjustments (consisting of normal and recurring adjustments) considered necessary for a fair statement of the results for the interim periods presented have been included. The results of operations for the interim periods are not necessarily indicative of results for the full year. It is the Company’s established practice to close its books for the quarters ending March, June and September on the Friday preceding the end of the calendar quarter. The interim unaudited condensed consolidated financial statements included herein have been prepared and are labeled based on that convention. The Company closes its books for annual periods on December 31 regardless of what day it falls on. Certain reclassifications have been made to conform prior-year amounts to the current-year presentation. Accounting Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of sales and costs of sales during the reporting period. The most significant of these estimates and assumptions for L-3 relate to contract revenue, profit and loss recognition, fair values of assets acquired and liabilities assumed in business combinations, market values for inventories reported at lower of cost or market, pension and post-retirement benefit obligations, stock-based employee compensation expense, income taxes, including the valuation of deferred tax assets, litigation reserves and environmental obligations, accrued product warranty costs, and the recoverability, useful lives and valuation of recorded amounts of long-lived assets, identifiable intangible assets and goodwill. Changes in estimates are reflected in the periods during which they become known. Actual amounts will differ from these estimates and could differ materially. Sales and profits on contracts that are covered by accounting standards for construction-type and production-type contracts and federal government contractors are recognized using percentage-of-completion (POC) methods of accounting. Approximately 46% of the Company’s net sales in 2014 were accounted for under contract accounting standards, of which approximately 40% were fixed-price type contracts and approximately 6% were cost-plus type contracts. For contracts that are accounted for under contract accounting standards, sales and profits are recognized based on: (1) a POC method of accounting (fixed-price contracts), (2) allowable costs incurred plus the estimated profit on those costs (cost-plus contracts), or (3) direct labor hours expended multiplied by the contractual fixed rate per hour plus incurred costs for material (time-and-material contracts). Sales and profits on fixed-price production contracts under which units are produced and delivered in a continuous or sequential process are recorded as units are delivered based on their contractual selling prices (the “units-of-delivery” method). Sales and profits on each fixed-price production contract under which units are not produced and delivered in a continuous or sequential process, or under which a relatively few number of units are produced, are recorded based on the ratio of actual cumulative costs incurred to total estimated costs at completion of the contract, multiplied by the total estimated contract revenue, less cumulative sales recognized in prior periods (the “cost-to-cost” method). Under both POC methods of accounting, a single estimated total profit margin is used to recognize profit for each contract over its entire period of performance, which can exceed one year. Accounting for the sales and profit on these fixed-price type contracts requires the preparation of estimates of: (1) the total contract revenue, (2) the total costs at completion, which is equal to the sum of the actual incurred costs to date on the contract and the estimated costs to complete the contract’s statement of work, and (3) the measurement of progress towards completion. The estimated profit or loss at completion on a contract is equal to the difference between the total estimated contract revenue and the total estimated cost at completion. The profit recorded on a contract in any period using either the units-of-delivery method or cost-to-cost method is equal to the current estimated total profit margin multiplied by the cumulative sales recognized, less the amount of cumulative profit previously recorded for the contract. Sales and profits on cost-plus type contracts that are covered by contract accounting standards are recognized as allowable costs are incurred on the contract, at an amount equal to the allowable costs plus the estimated profit on those costs. The estimated profit on a cost-plus type contract is fixed or variable based on the contractual fee arrangement. Incentive and award fees are the primary variable fee contractual arrangement types for the Company. Incentive and award fees on cost-plus type contracts are included as an element of total estimated contract revenues and are recorded as sales when a basis exists for the reasonable prediction of performance in relation to established contractual targets and the Company is able to make reasonably dependable estimates for them. Sales and profits on time-and-material type contracts are recognized on the basis of direct labor hours expended multiplied by the contractual fixed rate per hour, plus the actual costs of materials and other direct non-labor costs. Revisions or adjustments to estimates for a contract’s revenue, estimated costs at completion and estimated profit or loss are often required as work progresses under a contract, as experience is gained, as facts and circumstances change and as new information is obtained, even though the scope of work required under the contract may not change. Revisions or adjustments may also be required if contract modifications occur. The impact of revisions in profit (loss) estimates for all types of contracts subject to POC accounting are recognized on a cumulative catch-up basis in the period in which the revisions are made. The revisions in contract estimates, if significant, can materially affect the Company’s results of operations and cash flows, as well as reduce the valuations of receivables and inventories, and in some cases result in liabilities to complete contracts in a loss position. Aggregate net changes in contract estimates amounted to increases of $52 million, or 34% of consolidated operating income (8% of segment operating income) for the year-to-date period ended September 25, 2015, and increases of $71 million, or 9% of consolidated operating income for the year-to-date period ended September 26, 2014. For a more complete discussion of these estimates and assumptions, see the Annual Report on Form 10-K for the year ended December 31, 2014.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	9 Months Ended
	Sep. 25, 2015
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	3. Recently Issued Accounting Standards In July 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-11, to simplify the measurement of inventory. This update requires that inventory measured at first in, first out or average cost be measured at the lower of cost and net realizable value. This update is effective for interim and annual periods beginning after December 15, 2016. The Company is currently evaluating the expected impact of the adoption of this standard on its consolidated financial statements. In April 2015, the FASB issued ASU 2015-3, to simplify the presentation of debt issuance costs. This update requires that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of the associated debt liability, consistent with the required presentation for debt discounts. This update is effective for interim and annual periods beginning after December 15, 2015 and early adoption is permitted. The adoption of this standard will change the Company’s current practice of presenting debt issuance costs as an asset and will result in a reduction of total assets and total liabilities in an amount equal to the balance of unamortized debt issuance costs at each balance sheet date. The Company has not elected to early adopt this standard and debt issuance costs amounted to $22 million at September 25, 2015 and $27 million at December 31, 2014. In May 2014, the FASB issued ASU 2014-9, Revenue from Contracts with Customers Other accounting standard updates effective for interim and annual periods beginning after December 15, 2015 are not expected to have an impact on the Company’s financial position, results of operations or cash flows.

Acquisitions and Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 25, 2015
Business Combinations [Abstract]
Acquisitions and Divestitures	4. Acquisitions and Divestitures Business Acquisitions The business acquisitions discussed below are included in the Company’s results of operations from their respective dates of acquisition. 2015 Business Acquisitions CTC Aviation Group Acquisition. MITEQ, Inc. Acquisition. 2014 Business Acquisition Data Tactics Corporation Acquisition. Business Acquisitions Completed After September 25, 2015 ForceX, Inc. Acquisition. Unaudited Pro Forma Statements of Operations Data The following unaudited pro forma Statements of Operations data present the combined results of the Company and its business acquisitions completed during the year-to-date period ended September 25, 2015 and the year ended December 31, 2014, in each case assuming that the business acquisitions completed during these periods had occurred on January 1, 2014. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions, except per share data) Pro forma net sales $ 2,817 $ 2,973 $ 8,357 $ 9,021 Pro forma net (loss) income attributable to L-3 $ (299 ) $ 156 $ (71 ) $ 466 Pro forma diluted (loss) earnings per share $ (3.74 ) $ 1.80 $ (0.87 ) $ 5.27 The unaudited pro forma results disclosed in the table above are based on various assumptions and are not necessarily indicative of the results of operations that would have occurred had the Company completed these acquisitions on January 1, 2014. Business Divestitures During the year-to-date period ended September 25, 2015, the Company completed the sales of Marine Systems International (MSI), Broadcast Sports Inc. (BSI) and the Tinsley Product Line. The adjustments recorded by the Company related to the business divestitures are included in the loss related to business divestitures caption on the unaudited condensed consolidated statements of operations and are summarized and further discussed below. Third Quarter Ended Year-to-Date Ended September 25, September 25, (in millions) Loss on Tinsley Product Line divestiture $ (8 ) $ (8 ) Loss on BSI divestiture (1 ) (4 ) Gain on MSI divestiture — 4 Non-cash impairment charge related to MSI assets held for sale — (17 ) Loss on a forward contract to sell Euro proceeds from MSI divestiture — (4 ) Total loss related to the business divestitures $ (9 ) $ (29 ) MSI Divestiture. Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, The accounting standards for long-lived assets to be disposed of by sale require the Company to measure assets and liabilities of a disposal group, classified as held for sale, at the lower of its carrying amount or fair value less costs to sell, at the end of each reporting period. As a result of the decline in the estimated U.S. dollar equivalent divestiture proceeds due to the weakening of the Euro against the U.S. dollar, the carrying value of the MSI disposal group exceeded its fair value at March 27, 2015. Accordingly, a pre-tax non-cash impairment charge of $17 million ($12 million after income taxes) was recorded during the quarterly period ended March 27, 2015. In March 2015, L-3 entered into a forward contract to sell €285 million of the proceeds obtained from the divestiture of MSI at a rate of $1.0782. The Company accounted for this contract as an economic hedge and recorded a mark to market adjustment to earnings based on the fair value of the forward contract at March 27, 2015. Accordingly, the Company recorded an unrealized pre-tax loss of $5 million ($3 million after income taxes) during the quarterly period ended March 27, 2015. On May 29, 2015, upon settlement of the contract, the Company realized $4 million of the $5 million previously recorded pre-tax loss and recorded a $1 million pre-tax gain ($1 million after income taxes) in the quarterly period ended June 26, 2015. The major classes of assets and liabilities included as held for sale related to MSI are presented in the table below. December 31, (in millions) Assets Cash and cash equivalents $ 61 Billed receivables, net of allowances of $6 77 Contracts in process 70 Inventories 70 Other current assets 10 Total current assets 288 Goodwill 231 Other assets 28 Total assets classified as held for sale $ 547 Liabilities Accounts payable, trade $ 31 Accrued employment costs 22 Accrued expenses 33 Advance payments and billings in excess of costs incurred 55 Other current liabilities 21 Total current liabilities 162 Pension and postretirement benefits 56 Other liabilities 19 Total liabilities classified as held for sale $ 237 BSI Divestiture. Tinsley Product Line Divestiture. Net sales and income before income taxes for MSI, BSI and the Tinsley Product Line, included in L-3’s unaudited condensed consolidated statements of operations, are presented in the table below on an aggregate basis, and are included in income from continuing operations for all periods presented. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Net sales $ 1 $ 126 $ 201 $ 420 Income before income taxes $ 1 $ 3 $ 2 $ 13

Contracts in Process

Contracts in Process	9 Months Ended
	Sep. 25, 2015
Text Block [Abstract]
Contracts in Process	5. Contracts in Process The components of contracts in process are presented in the table below. September 25, December 31, (in millions) Unbilled contract receivables, gross $ 2,626 $ 2,280 Unliquidated progress payments (1,057 ) (887 ) Unbilled contract receivables, net 1,569 1,393 Inventoried contract costs, gross 1,033 997 Unliquidated progress payments (119 ) (95 ) Inventoried contract costs, net 914 902 Total contracts in process $ 2,483 $ 2,295 Inventoried Contract Costs. The table below presents a summary of G&A, IRAD and B&P costs included in inventoried contract costs and the changes to them, including amounts charged to cost of sales by the Company’s U.S. Government contractor businesses for the periods presented. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Amounts included in inventoried contract costs at beginning of the period $ 149 $ 146 $ 138 $ 133 Contract costs incurred: IRAD and B&P 70 70 210 213 Other G&A 219 230 640 645 Total 289 300 850 858 Amounts charged to cost of sales (269 ) (300 ) (819 ) (845 ) Amounts included in inventoried contract costs at end of the period $ 169 $ 146 $ 169 $ 146 The table below presents a summary of selling, general and administrative expenses and research and development expenses for the Company’s commercial businesses, which are expensed as incurred and included in cost of sales on the unaudited condensed consolidated statements of operations. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Selling, general and administrative expenses $ 53 $ 72 $ 198 $ 225 Research and development expenses 13 15 40 51 Total $ 66 $ 87 $ 238 $ 276

Inventories

Inventories	9 Months Ended
	Sep. 25, 2015
Inventory Disclosure [Abstract]
Inventories	6. Inventories Inventories at Lower of Cost or Market. September 25, December 31, (in millions) Raw materials, components and sub-assemblies $ 188 $ 127 Work in process 114 97 Finished goods 72 64 Total $ 374 $ 288

Goodwill and Identifiable Intan

Goodwill and Identifiable Intangible Assets	9 Months Ended
	Sep. 25, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Identifiable Intangible Assets	7. Goodwill and Identifiable Intangible Assets Goodwill. Electronic Aerospace Communication NSS Consolidated (in millions) Balance at December 31, 2014 $ 3,773 $ 1,730 $ 992 $ 1,006 $ 7,501 Business acquisitions (1) 177 — 11 — 188 Business divestitures (2) (12 ) — — — (12 ) Impairment loss — — — (491 ) (491 ) Foreign currency translation adjustments (3) (43 ) (31 ) — — (74 ) Balance at September 25, 2015 $ 3,895 $ 1,699 $ 1,003 $ 515 $ 7,112 (1) The increase in goodwill for the Electronic Systems segment was due to the L-3 CTC business acquisition. The increase in goodwill for the Communication Systems segment was due to the Miteq business acquisition. (2) The decrease in goodwill for the Electronic Systems segment was due to the divestitures of BSI and the Tinsley Product Line. (3) The decrease in goodwill presented in the Electronic Systems segment was due to the strengthening of the U.S. dollar against the Canadian dollar, the British pound, the Euro and the Australian dollar during the year-to-date period ended September 25, 2015. The decrease in goodwill presented in the Aerospace Systems segment was due to the strengthening of the U.S. dollar against the Canadian dollar during the year-to-date period ended September 25, 2015. As previously disclosed on October 29, 2015, the Company continues to evaluate strategic alternatives for NSS. These strategic alternatives could include, among other possibilities, a potential sale, spin-off or other divestiture transactions for the business. During the quarterly period ended September 25, 2015, a decline in the projected future cash flows of NSS indicated that the carrying amount of the goodwill for the NSS business may not be recoverable. As such, the Company performed the first step of the impairment test for the NSS business. The first step of the impairment test indicated that a portion of the $1,006 million of goodwill for the NSS business may not be recoverable. The Company performed the second step of the impairment test in accordance with the accounting standards for goodwill to measure the impairment loss and determined that the implied goodwill was $491 million lower than the carrying amount. Accordingly, the Company recorded a non-cash impairment charge of $491 million ($463 million after income taxes) for the impairment of goodwill. The goodwill impairment charge was due to a decline in the estimated fair value of the NSS business as a result of a decline in the projected future cash flows of NSS caused by NSS’s inability to achieve its planned 2015 orders, sales and operating income, primarily due to lower than expected new commercial and international business awards, and a reduced outlook for operating margin and international sales. The Company’s accumulated goodwill impairment losses were $549 million at September 25, 2015, of which $491 million, $43 million and $15 million were recorded in the NSS, Electronic Systems and Communication Systems segments, respectively. Identifiable Intangible Assets. September 25, 2015 December 31, 2014 Weighted Gross Accumulated Net Gross Accumulated Net (in years) (in millions) Customer contractual relationships 19 $ 461 $ 283 $ 178 $ 440 $ 262 $ 178 Technology 11 186 118 68 165 111 54 Other 18 27 17 10 27 16 11 Total 17 $ 674 $ 418 $ 256 $ 632 $ 389 $ 243 The table below presents amortization expense recorded by the Company for its identifiable intangible assets. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Amortization Expense $ 10 $ 11 $ 29 $ 32 Based on gross carrying amounts at September 25, 2015, the Company’s estimate of amortization expense for identifiable intangible assets for the years ending December 31, 2015 through 2019 is presented in the table below. Year Ending December 31, 2015 2016 2017 2018 2019 (in millions) Estimated amortization expense $ 38 $ 38 $ 35 $ 30 $ 27

Other Current Liabilities and O

Other Current Liabilities and Other Liabilities	9 Months Ended
	Sep. 25, 2015
Text Block [Abstract]
Other Current Liabilities and Other Liabilities	8. Other Current Liabilities and Other Liabilities The table below presents the components of other current liabilities. September 25, December 31, (in millions) Other Current Liabilities: Accruals for pending and threatened litigation (see Note 17) $ 45 $ 38 Estimated costs in excess of estimated contract value to complete contracts in process in a loss position 79 75 Accrued product warranty costs 59 59 Accrued interest 52 46 Deferred revenues 29 30 Other 132 150 Total other current liabilities $ 396 $ 398 The table below presents the components of other liabilities. September 25, December 31, (in millions) Other Liabilities: Non-current income taxes payable (see Note 10) $ 193 $ 196 Deferred compensation 45 43 Accrued workers’ compensation 35 38 Accrued product warranty costs 34 34 Notes payable and capital lease obligations 9 1 Other 87 70 Total other liabilities $ 403 $ 382 The table below presents the changes in the Company’s accrued product warranty costs. Year-to-Date Ended September 25, September 26, (in millions) Accrued product warranty costs: (1) Balance at January 1 $ 93 $ 99 Acquisitions during the period 1 — Accruals for product warranties issued during the period 46 53 Settlements made during the period (46 ) (46 ) Foreign currency translation adjustments (1 ) (1 ) Balance at end of period $ 93 $ 105 (1) Warranty obligations incurred in connection with long-term production contracts that are accounted for under the POC cost-to-cost method are included within the contract estimates at completion and are excluded from the above amounts. The balances above include both the current and non-current amounts.

Debt

Debt	9 Months Ended
	Sep. 25, 2015
Debt Disclosure [Abstract]
Debt	9. Debt The components of long-term debt and a reconciliation to the carrying amount of long-term debt are presented in the table below. September 25, December 31, (in millions) L-3 Communications: Borrowings under Amended and Restated Revolving Credit Facility (1) $ — $ — 3.95% Senior Notes due 2016 500 500 1.50% Senior Notes due 2017 350 350 5.20% Senior Notes due 2019 1,000 1,000 4.75% Senior Notes due 2020 800 800 4.95% Senior Notes due 2021 650 650 3.95% Senior Notes due 2024 650 650 Principal amount of long-term debt 3,950 3,950 Unamortized discounts (10 ) (11 ) Carrying amount of long-term debt $ 3,940 $ 3,939 (1) During the year-to-date period ended September 25, 2015, L-3 Communications’ aggregate borrowings and repayments under the Credit Facility were each $861 million. At September 25, 2015, L-3 Communications had the full availability of its $1 billion Credit Facility, which expires on February 3, 2017.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 25, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company and its subsidiaries file income tax returns in the U.S. Federal jurisdiction and various state and foreign jurisdictions. As of September 25, 2015, the statutes of limitations for the Company’s U.S. Federal income tax returns for the years ended December 31, 2010 through 2014 were open. In the second quarter of 2015, the Company reached agreements relating to the audit of the Company’s 2010 and 2011 U.S. Federal income tax returns with the U.S. Internal Revenue Service (IRS), as well as audits of several state and foreign jurisdictions. As a result of these agreements, the Company reversed previously accrued income tax expense of $10 million, including interest and penalties. The IRS commenced an audit of the Company’s U.S. Federal income tax return for 2012. The Company cannot predict the outcome of the audit at this time. The effective income tax rate for the year-to-date period ended September 25, 2015 is not meaningful because income tax expense was greater than pre-tax income during the period due to the goodwill impairment charge. The marginal income tax rate on the goodwill impairment charge relating to the NSS segment was 6% because a significant portion of the NSS goodwill is not deductible for tax. Excluding the goodwill impairment charge and related income tax benefit, the effective income tax rate for the year-to-date period ended September 25, 2015 would have decreased to 22.3%, compared to 29.5% for the same period last year primarily due to $36 million of tax benefits recorded in the quarterly period ended June 26, 2015, including: (1) $17 million of foreign tax benefits related to a legal restructuring of the Company’s foreign entities, (2) a $10 million benefit related to the resolution of various outstanding income tax matters with U.S. and foreign tax authorities, as discussed above, and (3) $9 million related to deferred tax benefits. As of September 25, 2015, the Company anticipates that unrecognized tax benefits will decrease by approximately $25 million over the next 12 months due to the potential resolution of unrecognized tax benefits involving several jurisdictions and tax periods. The actual amount of the decrease over the next 12 months could vary significantly depending on the ultimate timing and nature of any settlements. Non-current income taxes payable include accrued potential interest of $18 million ($11 million after income taxes) at September 25, 2015 and $15 million ($9 million after income taxes) at December 31, 2014, and potential penalties of $9 million at September 25, 2015 and December 31, 2014.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income (AOCI)	9 Months Ended
	Sep. 25, 2015
Equity [Abstract]
Accumulated Other Comprehensive (Loss) Income (AOCI)	11. Accumulated Other Comprehensive (Loss) Income (AOCI) The changes in the AOCI balances, including amounts reclassified from AOCI into net income, are presented in the table below. Foreign Unrealized Unrecognized Total (in millions) Balance at December 31, 2014 $ 19 $ (5 ) $ (598 ) $ (584 ) Other comprehensive loss before reclassifications, net of tax (125 ) (13 ) — (138 ) Amounts reclassified from AOCI, net of tax 41 10 41 92 Net current period other comprehensive (loss) income (84 ) (3 ) 41 (46 ) Balance at September 25, 2015 $ (65 ) $ (8 ) $ (557 ) $ (630 ) Balance at December 31, 2013 $ 142 $ 1 $ (253 ) $ (110 ) Other comprehensive loss before reclassifications, net of tax (57 ) (5 ) — (62 ) Amounts reclassified from AOCI, net of tax — 5 7 12 Net current period other comprehensive (loss) income (57 ) — 7 (50 ) Balance at September 26, 2014 $ 85 $ 1 $ (246 ) $ (160 ) Further details regarding the amounts reclassified from AOCI into net income are presented in the table below. Amount Reclassified from AOCI (a) Affected Line Item in the Unaudited Condensed Consolidated Statements of Operations Third Quarter Ended Year-to-Date Ended Details About AOCI Components September 25, September 26, September 25, September 26, (in millions) Foreign currency translation adjustment: MSI divestiture $ — $ — $ (41 ) $ — Loss related to business divestitures — — (41 ) — Income before income taxes — — — — Provision for income taxes $ — $ — $ (41 ) $ — Net income (Losses) gains on hedging instruments: MSI divestiture $ — $ — $ (2 ) $ — Loss related to business divestitures Other (4 ) 1 (10 ) (6 ) Cost of sales-products (4 ) 1 (12 ) (6 ) Income before income taxes — (1 ) 2 1 Provision for income taxes $ (4 ) $ — $ (10 ) $ (5 ) Net income Amortization of defined benefit pension items: MSI divestiture $ — $ — $ (14 ) $ — Loss related to business divestitures Net loss (17 ) (3 ) (50 ) (11 ) (b) (17 ) (3 ) (64 ) (11 ) Income before income taxes 7 1 23 4 Provision for income taxes $ (10 ) $ (2 ) $ (41 ) $ (7 ) Net income Total reclassification for the period $ (14 ) $ (2 ) $ (92 ) $ (12 ) Net income (a) Amounts in parenthesis indicate charges to the unaudited condensed consolidated statements of operations. (b) Amounts related to pension and postretirement benefit plans were reclassified from AOCI and recorded as a component of net periodic benefit cost (see Note 18 for additional information).

Equity

Equity	9 Months Ended
	Sep. 25, 2015
Equity [Abstract]
Equity	12. Equity On February 5, 2013, L-3 Holdings’ Board of Directors approved a share repurchase program that authorizes L-3 Holdings to repurchase up to $1.5 billion of its common stock through June 30, 2015. On December 4, 2014, L-3 Holdings’ Board of Directors approved a new share repurchase program that authorizes L-3 Holdings to repurchase up to an additional $1.5 billion of its common stock through June 30, 2017. Repurchases of L-3 Holdings’ common stock are made from time to time at management’s discretion in accordance with applicable U.S. Federal securities laws. The timing and actual number of shares to be repurchased in the future will depend on a variety of factors, including, but not limited to, the Company’s financial position, earnings, legal requirements, other investment opportunities (including acquisitions) and market conditions. L-3 Holdings repurchased 5,171,908 shares of its common stock at an average price of $117.01 per share for an aggregate amount of $605 million from January 1, 2015 through September 25, 2015. All share repurchases of L-3 Holdings’ common stock have been recorded as treasury shares. At September 25, 2015, the remaining dollar value under share repurchase programs authorized by L-3 Holdings’ From September 26, 2015 through October 23, 2015, L-3 Holdings repurchased 702,650 shares of its common stock at an average price of $106.70 per share for an aggregate amount of $75 million. On June 10, 2015, L-3 Holdings’ Board of Directors declared a cash dividend of $0.65 per share, paid on September 15, 2015 to shareholders of record at the close of business on August 17, 2015. During the year-to-date period ended September 25, 2015, the Company paid $163 million of cash dividends, including a $1 million net reduction of accrued dividends for employee held stock awards.

L-3 Holdings' Earnings (Loss) P

L-3 Holdings' Earnings (Loss) Per Common Share	9 Months Ended
	Sep. 25, 2015
Earnings Per Share [Abstract]
L-3 Holdings' Earnings (Loss) Per Common Share	13. L-3 Holdings’ Earnings (Loss) Per Common Share A reconciliation of basic and diluted earnings per share (EPS) is presented in the table below. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions, except per share data) Reconciliation of net (loss) income: Net (loss) income $ (296 ) $ 157 $ (63 ) $ 470 Net income attributable to noncontrolling interests (3 ) (3 ) (11 ) (9 ) Net (loss) income attributable to L-3 Holdings’ common shareholders $ (299 ) $ 154 $ (74 ) $ 461 Earnings (loss) per share attributable to L-3 Holdings’ common shareholders: Basic: Weighted average common shares outstanding 80.0 85.1 81.5 85.7 Basic (loss) earnings per share: Net (loss) income $ (3.74 ) $ 1.81 $ (0.91 ) $ 5.38 Diluted: Common and potential common shares (1) Weighted average common shares outstanding 80.0 85.1 81.5 85.7 Assumed exercise of stock options — 2.8 — 3.0 Unvested restricted stock awards — 1.5 — 1.6 Employee stock purchase plan contributions — — — 0.1 Performance unit awards — 0.1 — 0.1 Assumed purchase of common shares for treasury — (2.9 ) — (3.2 ) Assumed conversion of the CODES (2) — — — 1.1 Common and potential common shares 80.0 86.6 81.5 88.4 Diluted (loss) earnings per share: Net (loss) income $ (3.74 ) $ 1.78 $ (0.91 ) $ 5.21 (1) Due to a loss for the quarterly and year-to-date periods ended September 25, 2015, zero incremental weighted average potential common shares are included because the effect would be antidilutive. (2) L-3 Holdings’ 3% Convertible Contingent Debt Securities (CODES) due 2035 were retired on June 20, 2014, and were dilutive for the year-to-date period ended September 26, 2014 as the average market price of L-3 Holdings’ common stock during the period that the CODES were outstanding was greater than the price at which the CODES would have been convertible into L-3 Holdings’ common stock. As of June 18, 2014, the final date of conversion, the conversion price was $88.71. The computation of diluted EPS excludes shares for stock options, restricted stock awards, employee stock plan contributions and performance unit awards of 4.5 million for each of the quarterly and year-to-date periods ended September 25, 2015, and shares for stock options and employee stock purchase plan contributions of 0.6 million and 0.5 million for the quarterly and year-to-date periods ended September 26, 2014, respectively, as they were anti-dilutive.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 25, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	14. Fair Value Measurements L-3 applies the accounting standards for fair value measurements to all of the Company’s assets and liabilities that are measured and recorded at fair value. Fair value is defined as the price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants. The standards establish a fair value hierarchy that gives the highest priority to observable inputs and the lowest priority to unobservable inputs. The following table presents the fair value hierarchy level for each of the Company’s assets and liabilities that are measured and recorded at fair value on a recurring basis. September 25, 2015 December 31, 2014 Description Level 1 (1) Level 2 (2) Level 3 (3) Level 1 (1) Level 2 (2) Level 3 (3) (in millions) Assets Cash equivalents $ 182 $ — $ — $ 416 $ — $ — Derivatives (foreign currency forward contracts) — 2 — — 5 — Total assets $ 182 $ 2 $ — $ 416 $ 5 $ — Liabilities Derivatives (foreign currency forward contracts) $ — $ 15 $ — $ — $ 11 $ — (1) Level 1 is based on quoted market prices available in active markets for identical assets or liabilities as of the reporting date. Cash equivalents are primarily held in registered money market funds, which are valued using quoted market prices. (2) Level 2 is based on pricing inputs other than quoted prices in active markets, which are either directly or indirectly observable. The fair value is determined using a valuation model based on observable market inputs, including quoted foreign currency forward exchange rates and consideration of non-performance risk. (3) Level 3 is based on pricing inputs that are not observable and not corroborated by market data. The Company has no Level 3 assets or liabilities.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 25, 2015
Investments, All Other Investments [Abstract]
Financial Instruments	15. Financial Instruments At September 25, 2015 and December 31, 2014, the Company’s financial instruments consisted primarily of cash and cash equivalents, billed receivables, trade accounts payable, Senior Notes and foreign currency forward contracts. The carrying amounts of cash and cash equivalents, billed receivables and trade accounts payable are representative of their respective fair values because of the short-term maturities or the expected settlement dates of these instruments. The carrying amounts and estimated fair values of the Company’s other financial instruments are presented in the table below. September 25, 2015 December 31, 2014 Carrying Estimated Carrying Estimated (in millions) Senior Notes (1) $ 3,940 $ 4,068 $ 3,939 $ 4,178 Foreign currency forward contracts (2) $ (13 ) $ (13 ) $ (6 ) $ (6 ) (1) The Company measures the fair value of its Senior Notes using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market. (2) The Company measures the fair values of foreign currency forward contracts based on forward exchange rates. See Note 16 for additional disclosures regarding the notional amounts and fair values of foreign currency forward contracts.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 25, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	16. Derivative Financial Instruments The Company’s derivative financial instruments include foreign currency forward contracts, which are entered into for risk management purposes. Foreign Currency Forward Contracts. Currency Notional Amounts (in millions) Canadian dollar $ 141 U.S. dollar 94 Euro 21 British pound 2 Total $ 258 At September 25, 2015, the Company’s foreign currency forward contracts had maturities through 2018. The table below presents the location of the Company’s derivative instruments recorded at fair value on the condensed consolidated balance sheets. September 25, 2015 December 31, 2014 Other Other Other Other Other Other Other Other (in millions) Derivatives designated as hedging instruments: Foreign currency forward contracts (1)(2) $ 1 $ 1 $ 13 $ 2 $ 4 $ 1 $ 10 $ 1 Total derivative instruments $ 1 $ 1 $ 13 $ 2 $ 4 $ 1 $ 10 $ 1 (1) See Note 14 for a description of the fair value hierarchy related to the Company’s foreign currency forward contracts. (2) Assets held for sale at December 31, 2014 include $2 million, of other current assets relating to the fair value of derivative instruments, and liabilities held for sale at December 31, 2014 include $2 million of other current liabilities relating to the fair value of derivative instruments. The effect of gains or losses from foreign currency forward contracts was not material to the unaudited condensed consolidated statements of operations for the quarterly or year-to-date periods ended September 25, 2015 and September 26, 2014. At September 25, 2015, the estimated net amount of existing losses that are expected to be reclassified into income within the next 12 months is $10 million.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 25, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies Guarantees In connection with the spin-off of Engility Holdings, Inc. (Engility) in 2012, L-3 entered into a Distribution Agreement and several other agreements that govern certain aspects of L-3’s relationship with Engility, including employee matters, tax matters, transition services, and the future supplier/customer relationship between L-3 and Engility. These agreements generally provide cross-indemnities that, except as otherwise provided, are principally designed to place the financial responsibility for the obligations and liabilities of each entity with that respective entity. Engility has joint and several liability with L-3 to the U.S. Internal Revenue Service (IRS) for the consolidated U.S. Federal income taxes of L-3’s consolidated group for taxable periods in which Engility was a part of that group. However, the Tax Matters Agreement specifies the portion of this tax liability for which L-3 and Engility will each bear responsibility, and L-3 and Engility have agreed to indemnify each other against any amounts for which the other is not responsible. The Tax Matters Agreement also allocates responsibility between L-3 and Engility for other taxes, including special rules for allocating tax liabilities in the event that the spin-off is determined not to be tax-free. Though valid as between the parties, the Tax Matters Agreement is not binding on the IRS. The Company had two existing real estate lease agreements, which included residual guarantee amounts, were due to expire on August 31, 2015 and were accounted for as operating leases. Before the lease expiration date, the Company exercised an option to renew the leases for another five years, with similar lease terms, except the aggregate residual guarantee amount increased by $17 million to $40 million, reflecting the appreciation of the estimated fair value of the leased properties. The Company received $17 million in cash from the lessor at the inception of the new leases, which is included in cash flows from financing activities in the unaudited condensed consolidated statement of cash flows for the year-to-date period ended September 25, 2015, and recorded a deferred gain in other liabilities in the unaudited condensed consolidated balance sheet as of September 25, 2015. Procurement Regulations A substantial majority of the Company’s revenues are generated from providing products and services under legally binding agreements or contracts with U.S. Government and foreign government customers. U.S. Government contracts are subject to extensive legal and regulatory requirements, and, from time to time, agencies of the U.S. Government investigate whether such contracts were and are being conducted in accordance with these requirements. The Company is currently cooperating with the U.S. Government on several investigations from which civil, criminal or administrative proceedings have or could result and give rise to fines, penalties, compensatory and treble damages, restitution and/or forfeitures. In that regard, as of September 25, 2015, the Company has recognized an aggregate liability of $26 million in anticipation of a settlement related to a product specification matter regarding a holographic weapon sight product in the Warrior Systems sector of the Electronic Systems segment. The Company has other ongoing government investigations, including investigations into the pricing of certain contracts entered into by the Communication Systems segment. The Company does not currently anticipate that any of these investigations will have a material adverse effect, individually or in the aggregate, on its consolidated financial position, results of operations or cash flows. However, under U.S. Government regulations, an indictment of the Company by a federal grand jury, or an administrative finding against the Company as to its present responsibility to be a U.S. Government contractor or subcontractor, could result in the Company being suspended for a period of time from eligibility for awards of new government contracts or task orders or in a loss of export privileges. A conviction, or an administrative finding against the Company that satisfies the requisite level of seriousness, could result in debarment from contracting with the federal government for a specified term. In addition, all of the Company’s U.S. Government contracts: (1) are subject to audit and various pricing and cost controls, (2) include standard provisions for termination for the convenience of the U.S. Government or for default, and (3) are subject to cancellation if funds for contracts become unavailable. Foreign government contracts generally include comparable provisions relating to terminations for convenience or default, as well as other procurement clauses relevant to the foreign government. Litigation Matters The Company is also subject to litigation, proceedings, claims or assessments and various contingent liabilities incidental to its businesses, including those specified below. Furthermore, in connection with certain business acquisitions, the Company has assumed some or all claims against, and liabilities of, such acquired businesses, including both asserted and unasserted claims and liabilities. In accordance with the accounting standard for contingencies, the Company records a liability when management believes that it is both probable that a liability has been incurred and the Company can reasonably estimate the amount of the loss. Generally, the loss is recorded at the amount the Company expects to resolve the liability. The estimated amounts of liabilities recorded for pending and threatened litigation are disclosed in Note 8. Amounts recoverable from insurance contracts or third parties are recorded as assets when deemed probable. At September 25, 2015 and December 31, 2014, the Company recorded approximately $11 million of receivables for recoveries from insurance contracts or third parties in connection with the Bashkirian Airways matter discussed below. Legal defense costs are expensed as incurred. The Company believes it has recorded adequate provisions for its litigation matters. The Company reviews these provisions quarterly and adjusts these provisions to reflect the impact of negotiations, settlements, rulings, advice of legal counsel and other information and events pertaining to a particular matter. While it is reasonably possible that an unfavorable outcome may occur in one or more of the following matters, unless otherwise stated below, the Company believes that it is not probable that a loss has been incurred in any of these matters. With respect to the litigation matters below for which it is reasonably possible that an unfavorable outcome may occur, an estimate of loss or range of loss is disclosed when such amount or amounts can be reasonably estimated. Although the Company believes that it has valid defenses with respect to legal matters and investigations pending against it, the results of litigation can be difficult to predict, particularly those involving jury trials. Accordingly, the Company’s current judgment as to the likelihood of loss (or our current estimate as to the potential range of loss, if any) with respect to any particular litigation matter may turn out to be wrong. Therefore, it is possible that the financial position, results of operations or cash flows of the Company could be materially adversely affected in any particular period by the unfavorable resolution of one or more of these or other contingencies. Class Action. Government Inquiries Bashkirian Airways. HVC Alkmaar Qui Tam Action qui tam

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	9 Months Ended
	Sep. 25, 2015
Compensation and Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefits	18. Pension and Other Postretirement Benefits The following table summarizes the components of net periodic benefit cost for the Company’s pension and other postretirement benefit plans. Pension Plans Postretirement Benefit Plans Third Quarter Ended Year-to-Date Ended Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, September 25, September 26, September 25, September 26, (in millions) Components of net periodic benefit cost: Service cost $ 29 $ 26 $ 93 $ 80 $ — $ (2 ) $ 2 $ — Interest cost 38 37 112 110 1 4 5 8 Expected return on plan assets (51 ) (48 ) (155 ) (145 ) (1 ) (1 ) (3 ) (3 ) Amortization of prior service costs (credits) — — 1 1 — — (2 ) (1 ) Amortization of net loss (gain) 17 4 51 13 — (1 ) — (2 ) Curtailment loss 3 — 3 1 — (1 ) — (1 ) Net periodic benefit cost $ 36 $ 19 $ 105 $ 60 $ — $ (1 ) $ 2 $ 1 Contributions.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 25, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	19. Stock-Based Compensation During the year-to-date period ended September 25, 2015, the Company granted stock-based compensation under its Amended and Restated 2008 Long Term Performance Plan (2008 LTPP) in the form of stock options, restricted stock units and performance units. The stock-based compensation awards granted during the year-to-date period ended September 25, 2015 are further discussed below. Stock Options. Expected holding period (in years) 5.0 Expected volatility 21.4 % Expected dividend yield 2.4 % Risk-free interest rate 1.5 % Restricted Stock Units. Performance Units.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 25, 2015
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	20. Supplemental Cash Flow Information Year-to-Date Ended September 25, September 26, (in millions) Interest paid on outstanding debt $ 127 $ 123 Income tax payments 114 116 Income tax refunds 6 8

Segment Information

Segment Information	9 Months Ended
	Sep. 25, 2015
Segment Reporting [Abstract]
Segment Information	21. Segment Information The Company has four reportable segments, which are described in Note 1. The Company evaluates the performance of its reportable segments based on their sales and operating income. All corporate expenses are allocated to the Company’s operating segments using an allocation methodology prescribed by U.S. Government regulations for government contractors. Accordingly, all costs and expenses, except for the NSS goodwill impairment charge and the loss related to business divestitures (which were not included in the Company’s segment performance measures), are included in the Company’s measure of segment profitability. The tables below present net sales, operating income, depreciation and amortization and total assets by reportable segment. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Net Sales: Electronic Systems $ 1,014 $ 1,128 $ 3,113 $ 3,349 Aerospace Systems 1,068 1,037 3,092 3,173 Communication Systems 516 507 1,474 1,562 NSS 267 307 774 948 Elimination of intercompany sales (48 ) (39 ) (130 ) (116 ) Consolidated total $ 2,817 $ 2,940 $ 8,323 $ 8,916 Operating Income (Loss): Electronic Systems $ 123 $ 125 $ 356 $ 383 Aerospace Systems 103 64 148 196 Communication Systems 53 49 140 147 NSS 7 19 28 56 Segment total $ 286 $ 257 $ 672 $ 782 Loss related to business divestitures (1) (9 ) — (29 ) — Impairment charge (2) (491 ) — (491 ) — Consolidated total $ (214 ) $ 257 $ 152 $ 782 Depreciation and amortization: Electronic Systems $ 26 $ 30 $ 81 $ 89 Aerospace Systems 13 11 37 30 Communication Systems 12 13 37 38 NSS 3 2 9 8 Consolidated total $ 54 $ 56 $ 164 $ 165 (1) See Note 4 for information regarding the Company’s business divestitures. (2) Represents a non-cash goodwill impairment charge recorded in the third quarter of 2015 due to a decline in the estimated fair value of the NSS business. See Note 7 for additional information. September 25, December 31, (in millions) Total Assets: Electronic Systems $ 6,672 $ 6,287 Aerospace Systems 3,103 3,011 Communication Systems 1,990 1,997 NSS 777 1,287 Corporate 494 707 Assets held for sale — 547 Consolidated total $ 13,036 $ 13,836

Employee Severance and Terminat

Employee Severance and Termination Costs	9 Months Ended
	Sep. 25, 2015
Restructuring and Related Activities [Abstract]
Employee Severance and Termination Costs	22. Employee Severance and Termination Costs Consistent with the Company’s strategy to continuously improve its cost structure and right-size its businesses, especially in view of U.S. defense budget constraints, L-3 is completing employment reduction actions across several of its businesses to reduce both direct and indirect costs, including overhead and general and administrative costs. As a result of these initiatives and due to the impact of U.S. defense budget constraints at certain affected business units, the Company recorded $4 million and $10 million in employee severance and other termination costs, with respect to approximately 740 employees, during the quarterly and year-to-date periods ended September 25, 2015, respectively. During the year ended December 31, 2014, the Company recorded a total of $30 million in employee severance and other termination costs with respect to approximately 2,000 employees. Employee severance and other termination costs are reported within cost of sales on the unaudited condensed consolidated statements of operations. The remaining balance to be paid in connection with these initiatives was $6 million at September 25, 2015 and $11 million at December 31, 2014, which is expected to be paid primarily by the first half of 2016. Employee severance and other termination costs incurred by reportable segment for the quarterly and year-to-date periods ended September 25, 2015 and September 26, 2014 are presented in the table below. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Reportable Segment Electronic Systems $ 2 $ — $ 4 $ 14 Aerospace Systems 1 1 3 3 Communication Systems 1 2 3 5 NSS — — — 1 Consolidated $ 4 $ 3 $ 10 $ 23

Condensed Combining Financial I

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries	9 Months Ended
	Sep. 25, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries	23. Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries L-3 Communications is a 100% owned subsidiary of L-3 Holdings. The debt of L-3 Communications, including the Senior Notes and borrowings under amounts drawn against the Credit Facility is guaranteed, on a joint and several, full and unconditional basis, by certain of its domestic subsidiaries (the “Guarantor Subsidiaries”) and, in the case of the Credit Facility, by L-3 Holdings. See Note 10 to the audited consolidated financial statements for the year ended December 31, 2014, included in the Company’s Annual Report on Form 10-K for additional information. The foreign subsidiaries and certain domestic subsidiaries of L-3 Communications (the “Non-Guarantor Subsidiaries”) do not guarantee the debt of L-3 Communications or L-3 Holdings. None of the debt of L-3 Communications has been issued by its subsidiaries. There are no restrictions on the payment of dividends from the Guarantor Subsidiaries to L-3 Communications or from L-3 Communications to L-3 Holdings. Under the terms of the indentures governing the Senior Notes, the guarantees of the Senior Notes will automatically and unconditionally be released and discharged: (1) upon the release of all guarantees of all other outstanding indebtedness of L-3 Communications Corporation, or (2) upon the determination that such guarantor is no longer a “domestic subsidiary.” In addition, the guarantees of the Senior Notes will be automatically and unconditionally released and discharged in the event of a sale or other disposition of all of the assets of any guarantor, by way of merger, consolidation or otherwise, or a sale of all of the capital stock of such guarantor. The following unaudited condensed combining financial information presents the results of operations, financial position and cash flows of: (1) L-3 Holdings, excluding L-3 Communications and its consolidated subsidiaries (the Parent), (2) L-3 Communications, excluding its consolidated subsidiaries, (3) the Guarantor Subsidiaries, (4) the Non-Guarantor Subsidiaries, and (5) the eliminations to arrive at the information for L-3 on a consolidated basis. L-3 L-3 Guarantor Non- Eliminations Consolidated (in millions) Condensed Combining Balance Sheets: At September 25, 2015: Current assets: Cash and cash equivalents $ — $ 170 $ 1 $ 167 $ (15 ) $ 323 Billed receivables, net — 260 318 218 — 796 Contracts in process — 938 1,197 348 — 2,483 Other current assets — 413 163 117 — 693 Total current assets — 1,781 1,679 850 (15 ) 4,295 Goodwill — 2,317 3,777 1,018 — 7,112 Other assets — 800 552 277 — 1,629 Investment in and amounts due from consolidated subsidiaries 4,584 6,294 4,475 — (15,353 ) — Total assets $ 4,584 $ 11,192 $ 10,483 $ 2,145 $ (15,368 ) $ 13,036 Current liabilities $ — $ 931 $ 1,044 $ 504 $ (15 ) $ 2,464 Amounts due to consolidated subsidiaries — — — 16 (16 ) — Other long-term liabilities — 1,737 203 33 — 1,973 Long-term debt — 3,940 — — — 3,940 Total liabilities — 6,608 1,247 553 (31 ) 8,377 L-3 shareholders’ equity 4,584 4,584 9,236 1,592 (15,412 ) 4,584 Noncontrolling interests — — — — 75 75 Total equity 4,584 4,584 9,236 1,592 (15,337 ) 4,659 Total liabilities and equity $ 4,584 $ 11,192 $ 10,483 $ 2,145 $ (15,368 ) $ 13,036 At December 31, 2014: Current assets: Cash and cash equivalents $ — $ 361 $ 1 $ 142 $ (62 ) $ 442 Billed receivables, net — 320 329 203 — 852 Contracts in process — 867 1,144 284 — 2,295 Other current assets — 365 141 95 — 601 Assets held for sale — — 52 495 — 547 Total current assets — 1,913 1,667 1,219 (62 ) 4,737 Goodwill — 2,308 4,280 913 — 7,501 Other assets — 817 576 205 — 1,598 Investment in and amounts due from consolidated subsidiaries 5,285 6,855 4,157 — (16,297 ) — Total assets $ 5,285 $ 11,893 $ 10,680 $ 2,337 $ (16,359 ) $ 13,836 Current liabilities $ — $ 878 $ 1,017 $ 455 $ (62 ) $ 2,288 Liabilities held for sale — — 10 227 — 237 Amounts due to consolidated subsidiaries — — — 333 (333 ) — Other long-term liabilities — 1,791 190 31 — 2,012 Long-term debt — 3,939 — — — 3,939 Total liabilities — 6,608 1,217 1,046 (395 ) 8,476 L-3 shareholders’ equity 5,285 5,285 9,463 1,291 (16,039 ) 5,285 Noncontrolling interests — — — — 75 75 Total equity 5,285 5,285 9,463 1,291 (15,964 ) 5,360 Total liabilities and equity $ 5,285 $ 11,893 $ 10,680 $ 2,337 $ (16,359 ) $ 13,836 Condensed Combining Statements of Operations: For the quarter ended September 25, 2015: Total net sales $ — $ 873 $ 1,584 $ 449 $ (89 ) $ 2,817 Total cost of sales (12 ) (790 ) (1,442 ) (388 ) 101 (2,531 ) Loss related to business divestitures — (8 ) (1 ) — — (9 ) Impairment charge — — (491 ) — — (491 ) Operating (loss) income (12 ) 75 (350 ) 61 12 (214 ) Interest expense — (47 ) — — — (47 ) Interest and other income, net — 2 — 1 — 3 (Loss) income before income taxes (12 ) 30 (350 ) 62 12 (258 ) Benefit (provision) for income taxes 7 (10 ) (14 ) (14 ) (7 ) (38 ) Equity in net loss of consolidated subsidiaries (294 ) (319 ) — — 613 — Net (loss) income (299 ) (299 ) (364 ) 48 618 (296 ) Net income attributable to noncontrolling interests — — — — (3 ) (3 ) Net (loss) income attributable to L-3 $ (299 ) $ (299 ) $ (364 ) $ 48 $ 615 $ (299 ) Comprehensive loss attributable to L-3 $ (351 ) $ (351 ) $ (370 ) $ (9 ) $ 730 $ (351 ) For the quarter ended September 26, 2014: Total net sales $ — $ 860 $ 1,628 $ 525 $ (73 ) $ 2,940 Total cost of sales (10 ) (787 ) (1,500 ) (469 ) 83 (2,683 ) Operating (loss) income (10 ) 73 128 56 10 257 Interest expense — (46 ) (2 ) 1 — (47 ) Interest and other income, net — 4 — 1 — 5 (Loss) income before income taxes (10 ) 31 126 58 10 215 Benefit (provision) for income taxes 3 (8 ) (34 ) (16 ) (3 ) (58 ) Equity in net income of consolidated subsidiaries 161 131 — — (292 ) — Net income 154 154 92 42 (285 ) 157 Net income attributable to noncontrolling interests — — — — (3 ) (3 ) Net income attributable to L-3 $ 154 $ 154 $ 92 $ 42 $ (288 ) $ 154 Comprehensive income (loss) attributable to L-3 $ 90 $ 90 $ 89 $ (22 ) $ (157 ) $ 90 Condensed Combining Statements of Operations: For the year-to-date period ended September 25, 2015: Total net sales $ — $ 2,539 $ 4,574 $ 1,442 $ (232 ) $ 8,323 Total cost of sales (36 ) (2,313 ) (4,295 ) (1,275 ) 268 (7,651 ) (Loss) gain related to business divestitures — (13 ) (29 ) 13 — (29 ) Impairment charge — — (491 ) — — (491 ) Operating (loss) income (36 ) 213 (241 ) 180 36 152 Interest expense — (138 ) (1 ) — — (139 ) Interest and other income, net — 9 — 2 — 11 (Loss) income before income taxes (36 ) 84 (242 ) 182 36 24 Benefit (provision) for income taxes 11 (19 ) (33 ) (35 ) (11 ) (87 ) Equity in net loss of consolidated subsidiaries (49 ) (139 ) — — 188 — Net (loss) income (74 ) (74 ) (275 ) 147 213 (63 ) Net income attributable to noncontrolling interests — — — — (11 ) (11 ) Net (loss) income attributable to L-3 $ (74 ) $ (74 ) $ (275 ) $ 147 $ 202 $ (74 ) Comprehensive (loss) income attributable to L-3 $ (120 ) $ (120 ) $ (280 ) $ 73 $ 327 $ (120 ) For the year-to-date period ended September 26, 2014: Total net sales $ — $ 2,606 $ 4,908 $ 1,623 $ (221 ) $ 8,916 Total cost of sales (39 ) (2,354 ) (4,533 ) (1,468 ) 260 (8,134 ) Operating (loss) income (39 ) 252 375 155 39 782 Interest expense (2 ) (127 ) (2 ) — 2 (129 ) Interest and other income, net — 12 — 2 — 14 (Loss) income before income taxes (41 ) 137 373 157 41 667 Benefit (provision) for income taxes 12 (41 ) (110 ) (46 ) (12 ) (197 ) Equity in net income of consolidated subsidiaries 490 365 — — (855 ) — Net income 461 461 263 111 (826 ) 470 Net income attributable to noncontrolling interests — — — — (9 ) (9 ) Net income attributable to L-3 $ 461 $ 461 $ 263 $ 111 $ (835 ) $ 461 Comprehensive income attributable to L-3 $ 411 $ 411 $ 264 $ 53 $ (728 ) $ 411 Condensed Combining Statements of Cash Flows For the year-to-date period ended September 25, 2015: Operating activities: Net cash from operating activities $ 768 $ 337 $ 348 $ 66 $ (888 ) $ 631 Investing activities: Business acquisitions, net of cash acquired — (260 ) — — — (260 ) Proceeds from sale of businesses, net of closing date cash balances — 4 27 277 — 308 Investments in L-3 Communications (33 ) — — — 33 — Other investing activities — (63 ) (45 ) (26 ) — (134 ) Net cash (used in) from investing activities (33 ) (319 ) (18 ) 251 33 (86 ) Financing activities: Common stock repurchased (605 ) — — — — (605 ) Dividends paid on L-3 Holdings common stock (163 ) — — — — (163 ) Dividends paid to L-3 Holdings — (768 ) — — 768 — Investments from L-3 Holdings — 33 — — (33 ) — Other financing activities 33 526 (331 ) (338 ) 167 57 Net cash used in financing activities (735 ) (209 ) (331 ) (338 ) 902 (711 ) Effect of foreign currency exchange rate changes on cash — — — (14 ) — (14 ) Change in cash balance in assets held for sale — — 1 60 — 61 Net (decrease) increase in cash — (191 ) — 25 47 (119 ) Cash and cash equivalents, beginning of the period — 361 1 142 (62 ) 442 Cash and cash equivalents, end of the period $ — $ 170 $ 1 $ 167 $ (15 ) $ 323 For the year-to-date period ended September 26, 2014: Operating activities: Net cash from operating activities $ 1,506 $ 201 $ 382 $ 69 $ (1,553 ) $ 605 Investing activities: Business acquisitions, net of cash acquired — (57 ) — — — (57 ) Investments in L-3 Communications (87 ) — — — 87 — Other investing activities — (37 ) (52 ) (16 ) — (105 ) Net cash used in investing activities (87 ) (94 ) (52 ) (16 ) 87 (162 ) Financing activities: Proceeds from sale of Senior Notes — 996 — — — 996 Retirement of CODES (935 ) — — — — (935 ) Common stock repurchased (413 ) — — — — (413 ) Dividends paid on L-3 Holdings common stock (158 ) — — — — (158 ) Dividends paid to L-3 Holdings — (1,506 ) — — 1,506 — Investments from L-3 Holdings — 87 — — (87 ) — Other financing activities 87 388 (329 ) (66 ) 4 84 Net cash used in financing activities (1,419 ) (35 ) (329 ) (66 ) 1,423 (426 ) Effect of foreign currency exchange rate changes on cash — — — (9 ) — (9 ) Net increase (decrease) in cash — 72 1 (22 ) (43 ) 8 Cash and cash equivalents, beginning of the period — 258 — 261 (19 ) 500 Cash and cash equivalents, end of the period $ — $ 330 $ 1 $ 239 $ (62 ) $ 508

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 25, 2015
Accounting Policies [Abstract]
Principles of Consolidation and Reporting	Principles of Consolidation and Reporting The accompanying financial statements comprise the consolidated financial statements of L-3 Holdings and L-3 Communications. L-3 Holdings’ only asset is its investment in the common stock of L-3 Communications, its wholly-owned subsidiary, and its only obligations are: (1) its guarantee of borrowings under the Amended and Restated Revolving Credit Facility (Credit Facility) of L-3 Communications and (2) its guarantee of other contractual obligations of L-3 Communications and its subsidiaries. All issuances of and conversions into L-3 Holdings’ equity securities, including grants of stock options, restricted stock units and performance units by L-3 Holdings to employees and directors of L-3 Communications and its subsidiaries, have been reflected in the consolidated financial statements of L-3 Communications. As a result, the consolidated financial positions, results of operations and cash flows of L-3 Holdings and L-3 Communications are substantially the same. See Note 23 for additional information regarding the unaudited financial information of L-3 Communications and its subsidiaries. The unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the disclosures required by U.S. GAAP for a complete set of annual audited financial statements. The December 31, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. In the opinion of management, all adjustments (consisting of normal and recurring adjustments) considered necessary for a fair statement of the results for the interim periods presented have been included. The results of operations for the interim periods are not necessarily indicative of results for the full year. It is the Company’s established practice to close its books for the quarters ending March, June and September on the Friday preceding the end of the calendar quarter. The interim unaudited condensed consolidated financial statements included herein have been prepared and are labeled based on that convention. The Company closes its books for annual periods on December 31 regardless of what day it falls on. Certain reclassifications have been made to conform prior-year amounts to the current-year presentation.
Accounting Estimates	Accounting Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of sales and costs of sales during the reporting period. The most significant of these estimates and assumptions for L-3 relate to contract revenue, profit and loss recognition, fair values of assets acquired and liabilities assumed in business combinations, market values for inventories reported at lower of cost or market, pension and post-retirement benefit obligations, stock-based employee compensation expense, income taxes, including the valuation of deferred tax assets, litigation reserves and environmental obligations, accrued product warranty costs, and the recoverability, useful lives and valuation of recorded amounts of long-lived assets, identifiable intangible assets and goodwill. Changes in estimates are reflected in the periods during which they become known. Actual amounts will differ from these estimates and could differ materially. Sales and profits on contracts that are covered by accounting standards for construction-type and production-type contracts and federal government contractors are recognized using percentage-of-completion (POC) methods of accounting. Approximately 46% of the Company’s net sales in 2014 were accounted for under contract accounting standards, of which approximately 40% were fixed-price type contracts and approximately 6% were cost-plus type contracts. For contracts that are accounted for under contract accounting standards, sales and profits are recognized based on: (1) a POC method of accounting (fixed-price contracts), (2) allowable costs incurred plus the estimated profit on those costs (cost-plus contracts), or (3) direct labor hours expended multiplied by the contractual fixed rate per hour plus incurred costs for material (time-and-material contracts). Sales and profits on fixed-price production contracts under which units are produced and delivered in a continuous or sequential process are recorded as units are delivered based on their contractual selling prices (the “units-of-delivery” method). Sales and profits on each fixed-price production contract under which units are not produced and delivered in a continuous or sequential process, or under which a relatively few number of units are produced, are recorded based on the ratio of actual cumulative costs incurred to total estimated costs at completion of the contract, multiplied by the total estimated contract revenue, less cumulative sales recognized in prior periods (the “cost-to-cost” method). Under both POC methods of accounting, a single estimated total profit margin is used to recognize profit for each contract over its entire period of performance, which can exceed one year. Accounting for the sales and profit on these fixed-price type contracts requires the preparation of estimates of: (1) the total contract revenue, (2) the total costs at completion, which is equal to the sum of the actual incurred costs to date on the contract and the estimated costs to complete the contract’s statement of work, and (3) the measurement of progress towards completion. The estimated profit or loss at completion on a contract is equal to the difference between the total estimated contract revenue and the total estimated cost at completion. The profit recorded on a contract in any period using either the units-of-delivery method or cost-to-cost method is equal to the current estimated total profit margin multiplied by the cumulative sales recognized, less the amount of cumulative profit previously recorded for the contract. Sales and profits on cost-plus type contracts that are covered by contract accounting standards are recognized as allowable costs are incurred on the contract, at an amount equal to the allowable costs plus the estimated profit on those costs. The estimated profit on a cost-plus type contract is fixed or variable based on the contractual fee arrangement. Incentive and award fees are the primary variable fee contractual arrangement types for the Company. Incentive and award fees on cost-plus type contracts are included as an element of total estimated contract revenues and are recorded as sales when a basis exists for the reasonable prediction of performance in relation to established contractual targets and the Company is able to make reasonably dependable estimates for them. Sales and profits on time-and-material type contracts are recognized on the basis of direct labor hours expended multiplied by the contractual fixed rate per hour, plus the actual costs of materials and other direct non-labor costs. Revisions or adjustments to estimates for a contract’s revenue, estimated costs at completion and estimated profit or loss are often required as work progresses under a contract, as experience is gained, as facts and circumstances change and as new information is obtained, even though the scope of work required under the contract may not change. Revisions or adjustments may also be required if contract modifications occur. The impact of revisions in profit (loss) estimates for all types of contracts subject to POC accounting are recognized on a cumulative catch-up basis in the period in which the revisions are made. The revisions in contract estimates, if significant, can materially affect the Company’s results of operations and cash flows, as well as reduce the valuations of receivables and inventories, and in some cases result in liabilities to complete contracts in a loss position. Aggregate net changes in contract estimates amounted to increases of $52 million, or 34% of consolidated operating income (8% of segment operating income) for the year-to-date period ended September 25, 2015, and increases of $71 million, or 9% of consolidated operating income for the year-to-date period ended September 26, 2014. For a more complete discussion of these estimates and assumptions, see the Annual Report on Form 10-K for the year ended December 31, 2014.
Adoption of New Accounting Standards	In July 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-11, to simplify the measurement of inventory. This update requires that inventory measured at first in, first out or average cost be measured at the lower of cost and net realizable value. This update is effective for interim and annual periods beginning after December 15, 2016. The Company is currently evaluating the expected impact of the adoption of this standard on its consolidated financial statements. In April 2015, the FASB issued ASU 2015-3, to simplify the presentation of debt issuance costs. This update requires that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of the associated debt liability, consistent with the required presentation for debt discounts. This update is effective for interim and annual periods beginning after December 15, 2015 and early adoption is permitted. The adoption of this standard will change the Company’s current practice of presenting debt issuance costs as an asset and will result in a reduction of total assets and total liabilities in an amount equal to the balance of unamortized debt issuance costs at each balance sheet date. The Company has not elected to early adopt this standard and debt issuance costs amounted to $22 million at September 25, 2015 and $27 million at December 31, 2014. In May 2014, the FASB issued ASU 2014-9, Revenue from Contracts with Customers Other accounting standard updates effective for interim and annual periods beginning after December 15, 2015 are not expected to have an impact on the Company’s financial position, results of operations or cash flows.

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	9 Months Ended
	Sep. 25, 2015
Business Combinations [Abstract]
Unaudited Pro Forma Statements of Operations Data	The following unaudited pro forma Statements of Operations data present the combined results of the Company and its business acquisitions completed during the year-to-date period ended September 25, 2015 and the year ended December 31, 2014, in each case assuming that the business acquisitions completed during these periods had occurred on January 1, 2014. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions, except per share data) Pro forma net sales $ 2,817 $ 2,973 $ 8,357 $ 9,021 Pro forma net (loss) income attributable to L-3 $ (299 ) $ 156 $ (71 ) $ 466 Pro forma diluted (loss) earnings per share $ (3.74 ) $ 1.80 $ (0.87 ) $ 5.27
Components of Loss of Business Divestitures Included in Statements of Operations	The adjustments recorded by the Company related to the business divestitures are included in the loss related to business divestitures caption on the unaudited condensed consolidated statements of operations and are summarized and further discussed below. Third Quarter Ended Year-to-Date Ended September 25, September 25, (in millions) Loss on Tinsley Product Line divestiture $ (8 ) $ (8 ) Loss on BSI divestiture (1 ) (4 ) Gain on MSI divestiture — 4 Non-cash impairment charge related to MSI assets held for sale — (17 ) Loss on a forward contract to sell Euro proceeds from MSI divestiture — (4 ) Total loss related to the business divestitures $ (9 ) $ (29 )
Schedule of Major Classes of Assets and Liabilities Included as Held for Sale	The major classes of assets and liabilities included as held for sale related to MSI are presented in the table below. December 31, (in millions) Assets Cash and cash equivalents $ 61 Billed receivables, net of allowances of $6 77 Contracts in process 70 Inventories 70 Other current assets 10 Total current assets 288 Goodwill 231 Other assets 28 Total assets classified as held for sale $ 547 Liabilities Accounts payable, trade $ 31 Accrued employment costs 22 Accrued expenses 33 Advance payments and billings in excess of costs incurred 55 Other current liabilities 21 Total current liabilities 162 Pension and postretirement benefits 56 Other liabilities 19 Total liabilities classified as held for sale $ 237
Schedule of Net Sales and Income Before Income Taxes for MSI, BSI and Tinsley Product Line	Net sales and income before income taxes for MSI, BSI and the Tinsley Product Line, included in L-3’s unaudited condensed consolidated statements of operations, are presented in the table below on an aggregate basis, and are included in income from continuing operations for all periods presented. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Net sales $ 1 $ 126 $ 201 $ 420 Income before income taxes $ 1 $ 3 $ 2 $ 13

Contracts in Process (Tables)

Contracts in Process (Tables)	9 Months Ended
	Sep. 25, 2015
Text Block [Abstract]
Components of Contracts in Process	The components of contracts in process are presented in the table below. September 25, December 31, (in millions) Unbilled contract receivables, gross $ 2,626 $ 2,280 Unliquidated progress payments (1,057 ) (887 ) Unbilled contract receivables, net 1,569 1,393 Inventoried contract costs, gross 1,033 997 Unliquidated progress payments (119 ) (95 ) Inventoried contract costs, net 914 902 Total contracts in process $ 2,483 $ 2,295
General and Administrative, Independent Research and Development and Bid and Proposal Costs	The table below presents a summary of G&A, IRAD and B&P costs included in inventoried contract costs and the changes to them, including amounts charged to cost of sales by the Company’s U.S. Government contractor businesses for the periods presented. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Amounts included in inventoried contract costs at beginning of the period $ 149 $ 146 $ 138 $ 133 Contract costs incurred: IRAD and B&P 70 70 210 213 Other G&A 219 230 640 645 Total 289 300 850 858 Amounts charged to cost of sales (269 ) (300 ) (819 ) (845 ) Amounts included in inventoried contract costs at end of the period $ 169 $ 146 $ 169 $ 146
Selling, General and Administrative Expenses and Research and Development Expenses	The table below presents a summary of selling, general and administrative expenses and research and development expenses for the Company’s commercial businesses, which are expensed as incurred and included in cost of sales on the unaudited condensed consolidated statements of operations. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Selling, general and administrative expenses $ 53 $ 72 $ 198 $ 225 Research and development expenses 13 15 40 51 Total $ 66 $ 87 $ 238 $ 276

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 25, 2015
Inventory Disclosure [Abstract]
Inventories at Lower of Cost or Market	Inventories at Lower of Cost or Market. September 25, December 31, (in millions) Raw materials, components and sub-assemblies $ 188 $ 127 Work in process 114 97 Finished goods 72 64 Total $ 374 $ 288

Goodwill and Identifiable Int37

Goodwill and Identifiable Intangible Assets (Tables)	9 Months Ended
	Sep. 25, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Goodwill by Segment	The table below presents the changes in goodwill by segment for the year-to-date period ended September 25, 2015. Electronic Aerospace Communication NSS Consolidated (in millions) Balance at December 31, 2014 $ 3,773 $ 1,730 $ 992 $ 1,006 $ 7,501 Business acquisitions (1) 177 — 11 — 188 Business divestitures (2) (12 ) — — — (12 ) Impairment loss — — — (491 ) (491 ) Foreign currency translation adjustments (3) (43 ) (31 ) — — (74 ) Balance at September 25, 2015 $ 3,895 $ 1,699 $ 1,003 $ 515 $ 7,112 (1) The increase in goodwill for the Electronic Systems segment was due to the L-3 CTC business acquisition. The increase in goodwill for the Communication Systems segment was due to the Miteq business acquisition. (2) The decrease in goodwill for the Electronic Systems segment was due to the divestitures of BSI and the Tinsley Product Line. (3) The decrease in goodwill presented in the Electronic Systems segment was due to the strengthening of the U.S. dollar against the Canadian dollar, the British pound, the Euro and the Australian dollar during the year-to-date period ended September 25, 2015. The decrease in goodwill presented in the Aerospace Systems segment was due to the strengthening of the U.S. dollar against the Canadian dollar during the year-to-date period ended September 25, 2015.
Identifiable Intangible Assets	The table below presents information for the Company’s identifiable intangible assets that are subject to amortization. September 25, 2015 December 31, 2014 Weighted Gross Accumulated Net Gross Accumulated Net (in years) (in millions) Customer contractual relationships 19 $ 461 $ 283 $ 178 $ 440 $ 262 $ 178 Technology 11 186 118 68 165 111 54 Other 18 27 17 10 27 16 11 Total 17 $ 674 $ 418 $ 256 $ 632 $ 389 $ 243
Amortization Expense	The table below presents amortization expense recorded by the Company for its identifiable intangible assets. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Amortization Expense $ 10 $ 11 $ 29 $ 32
Estimated Amortization Expense	Based on gross carrying amounts at September 25, 2015, the Company’s estimate of amortization expense for identifiable intangible assets for the years ending December 31, 2015 through 2019 is presented in the table below. Year Ending December 31, 2015 2016 2017 2018 2019 (in millions) Estimated amortization expense $ 38 $ 38 $ 35 $ 30 $ 27

Other Current Liabilities and38

Other Current Liabilities and Other Liabilities (Tables)	9 Months Ended
	Sep. 25, 2015
Text Block [Abstract]
Other Current Liabilities	The table below presents the components of other current liabilities. September 25, December 31, (in millions) Other Current Liabilities: Accruals for pending and threatened litigation (see Note 17) $ 45 $ 38 Estimated costs in excess of estimated contract value to complete contracts in process in a loss position 79 75 Accrued product warranty costs 59 59 Accrued interest 52 46 Deferred revenues 29 30 Other 132 150 Total other current liabilities $ 396 $ 398
Other Liabilities	The table below presents the components of other liabilities. September 25, December 31, (in millions) Other Liabilities: Non-current income taxes payable (see Note 10) $ 193 $ 196 Deferred compensation 45 43 Accrued workers’ compensation 35 38 Accrued product warranty costs 34 34 Notes payable and capital lease obligations 9 1 Other 87 70 Total other liabilities $ 403 $ 382
Changes in Company's Accrued Product Warranty Costs	The table below presents the changes in the Company’s accrued product warranty costs. Year-to-Date Ended September 25, September 26, (in millions) Accrued product warranty costs: (1) Balance at January 1 $ 93 $ 99 Acquisitions during the period 1 — Accruals for product warranties issued during the period 46 53 Settlements made during the period (46 ) (46 ) Foreign currency translation adjustments (1 ) (1 ) Balance at end of period $ 93 $ 105 (1) Warranty obligations incurred in connection with long-term production contracts that are accounted for under the POC cost-to-cost method are included within the contract estimates at completion and are excluded from the above amounts. The balances above include both the current and non-current amounts.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 25, 2015
Debt Disclosure [Abstract]
Components of Long-Term Debt and Reconciliation to Carrying Amount of Long-Term Debt	The components of long-term debt and a reconciliation to the carrying amount of long-term debt are presented in the table below. September 25, December 31, (in millions) L-3 Communications: Borrowings under Amended and Restated Revolving Credit Facility (1) $ — $ — 3.95% Senior Notes due 2016 500 500 1.50% Senior Notes due 2017 350 350 5.20% Senior Notes due 2019 1,000 1,000 4.75% Senior Notes due 2020 800 800 4.95% Senior Notes due 2021 650 650 3.95% Senior Notes due 2024 650 650 Principal amount of long-term debt 3,950 3,950 Unamortized discounts (10 ) (11 ) Carrying amount of long-term debt $ 3,940 $ 3,939 (1) During the year-to-date period ended September 25, 2015, L-3 Communications’ aggregate borrowings and repayments under the Credit Facility were each $861 million. At September 25, 2015, L-3 Communications had the full availability of its $1 billion Credit Facility, which expires on February 3, 2017.

Accumulated Other Comprehensi40

Accumulated Other Comprehensive (Loss) Income (AOCI) (Tables)	9 Months Ended
	Sep. 25, 2015
Equity [Abstract]
Summary of Amounts Reclassified from AOCI into Net Income	The changes in the AOCI balances, including amounts reclassified from AOCI into net income, are presented in the table below. Foreign Unrealized Unrecognized Total (in millions) Balance at December 31, 2014 $ 19 $ (5 ) $ (598 ) $ (584 ) Other comprehensive loss before reclassifications, net of tax (125 ) (13 ) — (138 ) Amounts reclassified from AOCI, net of tax 41 10 41 92 Net current period other comprehensive (loss) income (84 ) (3 ) 41 (46 ) Balance at September 25, 2015 $ (65 ) $ (8 ) $ (557 ) $ (630 ) Balance at December 31, 2013 $ 142 $ 1 $ (253 ) $ (110 ) Other comprehensive loss before reclassifications, net of tax (57 ) (5 ) — (62 ) Amounts reclassified from AOCI, net of tax — 5 7 12 Net current period other comprehensive (loss) income (57 ) — 7 (50 ) Balance at September 26, 2014 $ 85 $ 1 $ (246 ) $ (160 ) Further details regarding the amounts reclassified from AOCI into net income are presented in the table below. Amount Reclassified from AOCI (a) Affected Line Item in the Unaudited Condensed Consolidated Statements of Operations Third Quarter Ended Year-to-Date Ended Details About AOCI Components September 25, September 26, September 25, September 26, (in millions) Foreign currency translation adjustment: MSI divestiture $ — $ — $ (41 ) $ — Loss related to business divestitures — — (41 ) — Income before income taxes — — — — Provision for income taxes $ — $ — $ (41 ) $ — Net income (Losses) gains on hedging instruments: MSI divestiture $ — $ — $ (2 ) $ — Loss related to business divestitures Other (4 ) 1 (10 ) (6 ) Cost of sales-products (4 ) 1 (12 ) (6 ) Income before income taxes — (1 ) 2 1 Provision for income taxes $ (4 ) $ — $ (10 ) $ (5 ) Net income Amortization of defined benefit pension items: MSI divestiture $ — $ — $ (14 ) $ — Loss related to business divestitures Net loss (17 ) (3 ) (50 ) (11 ) (b) (17 ) (3 ) (64 ) (11 ) Income before income taxes 7 1 23 4 Provision for income taxes $ (10 ) $ (2 ) $ (41 ) $ (7 ) Net income Total reclassification for the period $ (14 ) $ (2 ) $ (92 ) $ (12 ) Net income (a) Amounts in parenthesis indicate charges to the unaudited condensed consolidated statements of operations. (b) Amounts related to pension and postretirement benefit plans were reclassified from AOCI and recorded as a component of net periodic benefit cost (see Note 18 for additional information).

L-3 Holdings' Earnings (Loss)41

L-3 Holdings' Earnings (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 25, 2015
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Earnings per Share (EPS)	A reconciliation of basic and diluted earnings per share (EPS) is presented in the table below. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions, except per share data) Reconciliation of net (loss) income: Net (loss) income $ (296 ) $ 157 $ (63 ) $ 470 Net income attributable to noncontrolling interests (3 ) (3 ) (11 ) (9 ) Net (loss) income attributable to L-3 Holdings’ common shareholders $ (299 ) $ 154 $ (74 ) $ 461 Earnings (loss) per share attributable to L-3 Holdings’ common shareholders: Basic: Weighted average common shares outstanding 80.0 85.1 81.5 85.7 Basic (loss) earnings per share: Net (loss) income $ (3.74 ) $ 1.81 $ (0.91 ) $ 5.38 Diluted: Common and potential common shares (1) Weighted average common shares outstanding 80.0 85.1 81.5 85.7 Assumed exercise of stock options — 2.8 — 3.0 Unvested restricted stock awards — 1.5 — 1.6 Employee stock purchase plan contributions — — — 0.1 Performance unit awards — 0.1 — 0.1 Assumed purchase of common shares for treasury — (2.9 ) — (3.2 ) Assumed conversion of the CODES (2) — — — 1.1 Common and potential common shares 80.0 86.6 81.5 88.4 Diluted (loss) earnings per share: Net (loss) income $ (3.74 ) $ 1.78 $ (0.91 ) $ 5.21 (1) Due to a loss for the quarterly and year-to-date periods ended September 25, 2015, zero incremental weighted average potential common shares are included because the effect would be antidilutive. (2) L-3 Holdings’ 3% Convertible Contingent Debt Securities (CODES) due 2035 were retired on June 20, 2014, and were dilutive for the year-to-date period ended September 26, 2014 as the average market price of L-3 Holdings’ common stock during the period that the CODES were outstanding was greater than the price at which the CODES would have been convertible into L-3 Holdings’ common stock. As of June 18, 2014, the final date of conversion, the conversion price was $88.71.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 25, 2015
Fair Value Disclosures [Abstract]
Company's Assets and Liabilities at Fair Value on Recurring Basis	The following table presents the fair value hierarchy level for each of the Company’s assets and liabilities that are measured and recorded at fair value on a recurring basis. September 25, 2015 December 31, 2014 Description Level 1 (1) Level 2 (2) Level 3 (3) Level 1 (1) Level 2 (2) Level 3 (3) (in millions) Assets Cash equivalents $ 182 $ — $ — $ 416 $ — $ — Derivatives (foreign currency forward contracts) — 2 — — 5 — Total assets $ 182 $ 2 $ — $ 416 $ 5 $ — Liabilities Derivatives (foreign currency forward contracts) $ — $ 15 $ — $ — $ 11 $ — (1) Level 1 is based on quoted market prices available in active markets for identical assets or liabilities as of the reporting date. Cash equivalents are primarily held in registered money market funds, which are valued using quoted market prices. (2) Level 2 is based on pricing inputs other than quoted prices in active markets, which are either directly or indirectly observable. The fair value is determined using a valuation model based on observable market inputs, including quoted foreign currency forward exchange rates and consideration of non-performance risk. (3) Level 3 is based on pricing inputs that are not observable and not corroborated by market data. The Company has no Level 3 assets or liabilities.

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 25, 2015
Investments, All Other Investments [Abstract]
Carrying Amounts and Estimated Fair Values of Company's Long-Term Debt and Foreign Currency Forward Contracts	The carrying amounts and estimated fair values of the Company’s other financial instruments are presented in the table below. September 25, 2015 December 31, 2014 Carrying Estimated Carrying Estimated (in millions) Senior Notes (1) $ 3,940 $ 4,068 $ 3,939 $ 4,178 Foreign currency forward contracts (2) $ (13 ) $ (13 ) $ (6 ) $ (6 ) (1) The Company measures the fair value of its Senior Notes using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market. (2) The Company measures the fair values of foreign currency forward contracts based on forward exchange rates. See Note 16 for additional disclosures regarding the notional amounts and fair values of foreign currency forward contracts.

Derivative Financial Instrume44

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 25, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts of Company's Outstanding Foreign Currency Forward Contracts by Currency	The table below presents the notional amounts of the Company’s outstanding foreign currency forward contracts by currency at September 25, 2015. Currency Notional Amounts (in millions) Canadian dollar $ 141 U.S. dollar 94 Euro 21 British pound 2 Total $ 258
Location of Company's Derivative Instruments Recorded at Fair Value on Condensed Consolidated Balance Sheets	The table below presents the location of the Company’s derivative instruments recorded at fair value on the condensed consolidated balance sheets. September 25, 2015 December 31, 2014 Other Other Other Other Other Other Other Other (in millions) Derivatives designated as hedging instruments: Foreign currency forward contracts (1)(2) $ 1 $ 1 $ 13 $ 2 $ 4 $ 1 $ 10 $ 1 Total derivative instruments $ 1 $ 1 $ 13 $ 2 $ 4 $ 1 $ 10 $ 1 (1) See Note 14 for a description of the fair value hierarchy related to the Company’s foreign currency forward contracts. (2) Assets held for sale at December 31, 2014 include $2 million, of other current assets relating to the fair value of derivative instruments, and liabilities held for sale at December 31, 2014 include $2 million of other current liabilities relating to the fair value of derivative instruments.

Pension and Other Postretirem45

Pension and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 25, 2015
Compensation and Retirement Disclosure [Abstract]
Components of Net Periodic Benefit Cost	The following table summarizes the components of net periodic benefit cost for the Company’s pension and other postretirement benefit plans. Pension Plans Postretirement Benefit Plans Third Quarter Ended Year-to-Date Ended Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, September 25, September 26, September 25, September 26, (in millions) Components of net periodic benefit cost: Service cost $ 29 $ 26 $ 93 $ 80 $ — $ (2 ) $ 2 $ — Interest cost 38 37 112 110 1 4 5 8 Expected return on plan assets (51 ) (48 ) (155 ) (145 ) (1 ) (1 ) (3 ) (3 ) Amortization of prior service costs (credits) — — 1 1 — — (2 ) (1 ) Amortization of net loss (gain) 17 4 51 13 — (1 ) — (2 ) Curtailment loss 3 — 3 1 — (1 ) — (1 ) Net periodic benefit cost $ 36 $ 19 $ 105 $ 60 $ — $ (1 ) $ 2 $ 1

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 25, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted Average Assumptions in Valuation Model	The weighted average assumptions used in the valuation model for this grant are presented in the table below. Expected holding period (in years) 5.0 Expected volatility 21.4 % Expected dividend yield 2.4 % Risk-free interest rate 1.5 %

Supplemental Cash Flow Inform47

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 25, 2015
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Year-to-Date Ended September 25, September 26, (in millions) Interest paid on outstanding debt $ 127 $ 123 Income tax payments 114 116 Income tax refunds 6 8

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 25, 2015
Segment Reporting [Abstract]
Summary of Segment Information	The tables below present net sales, operating income, depreciation and amortization and total assets by reportable segment. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Net Sales: Electronic Systems $ 1,014 $ 1,128 $ 3,113 $ 3,349 Aerospace Systems 1,068 1,037 3,092 3,173 Communication Systems 516 507 1,474 1,562 NSS 267 307 774 948 Elimination of intercompany sales (48 ) (39 ) (130 ) (116 ) Consolidated total $ 2,817 $ 2,940 $ 8,323 $ 8,916 Operating Income (Loss): Electronic Systems $ 123 $ 125 $ 356 $ 383 Aerospace Systems 103 64 148 196 Communication Systems 53 49 140 147 NSS 7 19 28 56 Segment total $ 286 $ 257 $ 672 $ 782 Loss related to business divestitures (1) (9 ) — (29 ) — Impairment charge (2) (491 ) — (491 ) — Consolidated total $ (214 ) $ 257 $ 152 $ 782 Depreciation and amortization: Electronic Systems $ 26 $ 30 $ 81 $ 89 Aerospace Systems 13 11 37 30 Communication Systems 12 13 37 38 NSS 3 2 9 8 Consolidated total $ 54 $ 56 $ 164 $ 165 (1) See Note 4 for information regarding the Company’s business divestitures. (2) Represents a non-cash goodwill impairment charge recorded in the third quarter of 2015 due to a decline in the estimated fair value of the NSS business. See Note 7 for additional information. September 25, December 31, (in millions) Total Assets: Electronic Systems $ 6,672 $ 6,287 Aerospace Systems 3,103 3,011 Communication Systems 1,990 1,997 NSS 777 1,287 Corporate 494 707 Assets held for sale — 547 Consolidated total $ 13,036 $ 13,836

Employee Severance and Termin49

Employee Severance and Termination Costs (Tables)	9 Months Ended
	Sep. 25, 2015
Restructuring and Related Activities [Abstract]
Employee Severance and Other Termination Costs Incurred by Reportable Segment	Employee severance and other termination costs incurred by reportable segment for the quarterly and year-to-date periods ended September 25, 2015 and September 26, 2014 are presented in the table below. Third Quarter Ended Year-to-Date Ended September 25, September 26, September 25, September 26, (in millions) Reportable Segment Electronic Systems $ 2 $ — $ 4 $ 14 Aerospace Systems 1 1 3 3 Communication Systems 1 2 3 5 NSS — — — 1 Consolidated $ 4 $ 3 $ 10 $ 23

Condensed Combining Financial50

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries (Tables)	9 Months Ended
	Sep. 25, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Combining Balance Sheets	The following unaudited condensed combining financial information presents the results of operations, financial position and cash flows of: (1) L-3 Holdings, excluding L-3 Communications and its consolidated subsidiaries (the Parent), (2) L-3 Communications, excluding its consolidated subsidiaries, (3) the Guarantor Subsidiaries, (4) the Non-Guarantor Subsidiaries, and (5) the eliminations to arrive at the information for L-3 on a consolidated basis. L-3 L-3 Guarantor Non- Eliminations Consolidated (in millions) Condensed Combining Balance Sheets: At September 25, 2015: Current assets: Cash and cash equivalents $ — $ 170 $ 1 $ 167 $ (15 ) $ 323 Billed receivables, net — 260 318 218 — 796 Contracts in process — 938 1,197 348 — 2,483 Other current assets — 413 163 117 — 693 Total current assets — 1,781 1,679 850 (15 ) 4,295 Goodwill — 2,317 3,777 1,018 — 7,112 Other assets — 800 552 277 — 1,629 Investment in and amounts due from consolidated subsidiaries 4,584 6,294 4,475 — (15,353 ) — Total assets $ 4,584 $ 11,192 $ 10,483 $ 2,145 $ (15,368 ) $ 13,036 Current liabilities $ — $ 931 $ 1,044 $ 504 $ (15 ) $ 2,464 Amounts due to consolidated subsidiaries — — — 16 (16 ) — Other long-term liabilities — 1,737 203 33 — 1,973 Long-term debt — 3,940 — — — 3,940 Total liabilities — 6,608 1,247 553 (31 ) 8,377 L-3 shareholders’ equity 4,584 4,584 9,236 1,592 (15,412 ) 4,584 Noncontrolling interests — — — — 75 75 Total equity 4,584 4,584 9,236 1,592 (15,337 ) 4,659 Total liabilities and equity $ 4,584 $ 11,192 $ 10,483 $ 2,145 $ (15,368 ) $ 13,036 At December 31, 2014: Current assets: Cash and cash equivalents $ — $ 361 $ 1 $ 142 $ (62 ) $ 442 Billed receivables, net — 320 329 203 — 852 Contracts in process — 867 1,144 284 — 2,295 Other current assets — 365 141 95 — 601 Assets held for sale — — 52 495 — 547 Total current assets — 1,913 1,667 1,219 (62 ) 4,737 Goodwill — 2,308 4,280 913 — 7,501 Other assets — 817 576 205 — 1,598 Investment in and amounts due from consolidated subsidiaries 5,285 6,855 4,157 — (16,297 ) — Total assets $ 5,285 $ 11,893 $ 10,680 $ 2,337 $ (16,359 ) $ 13,836 Current liabilities $ — $ 878 $ 1,017 $ 455 $ (62 ) $ 2,288 Liabilities held for sale — — 10 227 — 237 Amounts due to consolidated subsidiaries — — — 333 (333 ) — Other long-term liabilities — 1,791 190 31 — 2,012 Long-term debt — 3,939 — — — 3,939 Total liabilities — 6,608 1,217 1,046 (395 ) 8,476 L-3 shareholders’ equity 5,285 5,285 9,463 1,291 (16,039 ) 5,285 Noncontrolling interests — — — — 75 75 Total equity 5,285 5,285 9,463 1,291 (15,964 ) 5,360 Total liabilities and equity $ 5,285 $ 11,893 $ 10,680 $ 2,337 $ (16,359 ) $ 13,836
Condensed Combining Statements of Operations	Condensed Combining Statements of Operations: For the quarter ended September 25, 2015: Total net sales $ — $ 873 $ 1,584 $ 449 $ (89 ) $ 2,817 Total cost of sales (12 ) (790 ) (1,442 ) (388 ) 101 (2,531 ) Loss related to business divestitures — (8 ) (1 ) — — (9 ) Impairment charge — — (491 ) — — (491 ) Operating (loss) income (12 ) 75 (350 ) 61 12 (214 ) Interest expense — (47 ) — — — (47 ) Interest and other income, net — 2 — 1 — 3 (Loss) income before income taxes (12 ) 30 (350 ) 62 12 (258 ) Benefit (provision) for income taxes 7 (10 ) (14 ) (14 ) (7 ) (38 ) Equity in net loss of consolidated subsidiaries (294 ) (319 ) — — 613 — Net (loss) income (299 ) (299 ) (364 ) 48 618 (296 ) Net income attributable to noncontrolling interests — — — — (3 ) (3 ) Net (loss) income attributable to L-3 $ (299 ) $ (299 ) $ (364 ) $ 48 $ 615 $ (299 ) Comprehensive loss attributable to L-3 $ (351 ) $ (351 ) $ (370 ) $ (9 ) $ 730 $ (351 ) For the quarter ended September 26, 2014: Total net sales $ — $ 860 $ 1,628 $ 525 $ (73 ) $ 2,940 Total cost of sales (10 ) (787 ) (1,500 ) (469 ) 83 (2,683 ) Operating (loss) income (10 ) 73 128 56 10 257 Interest expense — (46 ) (2 ) 1 — (47 ) Interest and other income, net — 4 — 1 — 5 (Loss) income before income taxes (10 ) 31 126 58 10 215 Benefit (provision) for income taxes 3 (8 ) (34 ) (16 ) (3 ) (58 ) Equity in net income of consolidated subsidiaries 161 131 — — (292 ) — Net income 154 154 92 42 (285 ) 157 Net income attributable to noncontrolling interests — — — — (3 ) (3 ) Net income attributable to L-3 $ 154 $ 154 $ 92 $ 42 $ (288 ) $ 154 Comprehensive income (loss) attributable to L-3 $ 90 $ 90 $ 89 $ (22 ) $ (157 ) $ 90 Condensed Combining Statements of Operations: For the year-to-date period ended September 25, 2015: Total net sales $ — $ 2,539 $ 4,574 $ 1,442 $ (232 ) $ 8,323 Total cost of sales (36 ) (2,313 ) (4,295 ) (1,275 ) 268 (7,651 ) (Loss) gain related to business divestitures — (13 ) (29 ) 13 — (29 ) Impairment charge — — (491 ) — — (491 ) Operating (loss) income (36 ) 213 (241 ) 180 36 152 Interest expense — (138 ) (1 ) — — (139 ) Interest and other income, net — 9 — 2 — 11 (Loss) income before income taxes (36 ) 84 (242 ) 182 36 24 Benefit (provision) for income taxes 11 (19 ) (33 ) (35 ) (11 ) (87 ) Equity in net loss of consolidated subsidiaries (49 ) (139 ) — — 188 — Net (loss) income (74 ) (74 ) (275 ) 147 213 (63 ) Net income attributable to noncontrolling interests — — — — (11 ) (11 ) Net (loss) income attributable to L-3 $ (74 ) $ (74 ) $ (275 ) $ 147 $ 202 $ (74 ) Comprehensive (loss) income attributable to L-3 $ (120 ) $ (120 ) $ (280 ) $ 73 $ 327 $ (120 ) For the year-to-date period ended September 26, 2014: Total net sales $ — $ 2,606 $ 4,908 $ 1,623 $ (221 ) $ 8,916 Total cost of sales (39 ) (2,354 ) (4,533 ) (1,468 ) 260 (8,134 ) Operating (loss) income (39 ) 252 375 155 39 782 Interest expense (2 ) (127 ) (2 ) — 2 (129 ) Interest and other income, net — 12 — 2 — 14 (Loss) income before income taxes (41 ) 137 373 157 41 667 Benefit (provision) for income taxes 12 (41 ) (110 ) (46 ) (12 ) (197 ) Equity in net income of consolidated subsidiaries 490 365 — — (855 ) — Net income 461 461 263 111 (826 ) 470 Net income attributable to noncontrolling interests — — — — (9 ) (9 ) Net income attributable to L-3 $ 461 $ 461 $ 263 $ 111 $ (835 ) $ 461 Comprehensive income attributable to L-3 $ 411 $ 411 $ 264 $ 53 $ (728 ) $ 411
Condensed Combining Statements of Cash Flows	Condensed Combining Statements of Cash Flows For the year-to-date period ended September 25, 2015: Operating activities: Net cash from operating activities $ 768 $ 337 $ 348 $ 66 $ (888 ) $ 631 Investing activities: Business acquisitions, net of cash acquired — (260 ) — — — (260 ) Proceeds from sale of businesses, net of closing date cash balances — 4 27 277 — 308 Investments in L-3 Communications (33 ) — — — 33 — Other investing activities — (63 ) (45 ) (26 ) — (134 ) Net cash (used in) from investing activities (33 ) (319 ) (18 ) 251 33 (86 ) Financing activities: Common stock repurchased (605 ) — — — — (605 ) Dividends paid on L-3 Holdings common stock (163 ) — — — — (163 ) Dividends paid to L-3 Holdings — (768 ) — — 768 — Investments from L-3 Holdings — 33 — — (33 ) — Other financing activities 33 526 (331 ) (338 ) 167 57 Net cash used in financing activities (735 ) (209 ) (331 ) (338 ) 902 (711 ) Effect of foreign currency exchange rate changes on cash — — — (14 ) — (14 ) Change in cash balance in assets held for sale — — 1 60 — 61 Net (decrease) increase in cash — (191 ) — 25 47 (119 ) Cash and cash equivalents, beginning of the period — 361 1 142 (62 ) 442 Cash and cash equivalents, end of the period $ — $ 170 $ 1 $ 167 $ (15 ) $ 323 For the year-to-date period ended September 26, 2014: Operating activities: Net cash from operating activities $ 1,506 $ 201 $ 382 $ 69 $ (1,553 ) $ 605 Investing activities: Business acquisitions, net of cash acquired — (57 ) — — — (57 ) Investments in L-3 Communications (87 ) — — — 87 — Other investing activities — (37 ) (52 ) (16 ) — (105 ) Net cash used in investing activities (87 ) (94 ) (52 ) (16 ) 87 (162 ) Financing activities: Proceeds from sale of Senior Notes — 996 — — — 996 Retirement of CODES (935 ) — — — — (935 ) Common stock repurchased (413 ) — — — — (413 ) Dividends paid on L-3 Holdings common stock (158 ) — — — — (158 ) Dividends paid to L-3 Holdings — (1,506 ) — — 1,506 — Investments from L-3 Holdings — 87 — — (87 ) — Other financing activities 87 388 (329 ) (66 ) 4 84 Net cash used in financing activities (1,419 ) (35 ) (329 ) (66 ) 1,423 (426 ) Effect of foreign currency exchange rate changes on cash — — — (9 ) — (9 ) Net increase (decrease) in cash — 72 1 (22 ) (43 ) 8 Cash and cash equivalents, beginning of the period — 258 — 261 (19 ) 500 Cash and cash equivalents, end of the period $ — $ 330 $ 1 $ 239 $ (62 ) $ 508

Description of Business - Addit

Description of Business - Additional Information (Detail)	9 Months Ended
	Sep. 25, 2015Segment
Disclosure Description Of Business Additional Information [Abstract]
Number of reportable segments	4

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Accounting Policies [Abstract]
Percentage of sales accounted for under contract accounting standards	46.00%
Percentage of fixed-price type contracts	40.00%
Percentage of cost-plus type contracts	6.00%
Period of performance for contracts accounted for under the percentage-of-completion method of accounting, minimum	1 year
Aggregate net changes in contract estimates amounted to increases of consolidated operating income	$ 52	$ 71
Increases in percentage of aggregate net changes in contract estimates of segment operating income	8.00%
Increases in percentage of aggregate net changes in contract estimates of consolidated operating income	34.00%	9.00%

Recently Issued Accounting St53

Recently Issued Accounting Standards - Additional Information (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Debt issuance costs	$ 22	$ 27

Acquisitions and Divestitures -

Acquisitions and Divestitures - Additional Information (Detail) € in Millions, £ in Millions, $ in Millions

May. 29, 2015USD ($)

Sep. 25, 2015USD ($)

Jun. 26, 2015USD ($)

Mar. 27, 2015USD ($)

Sep. 25, 2015USD ($)

Oct. 13, 2015USD ($)

Jul. 27, 2015USD ($)

May. 29, 2015EUR (€)

May. 27, 2015USD ($)

May. 27, 2015GBP (£)

Apr. 24, 2015USD ($)

Mar. 27, 2015EUR (€)€ / $

Jan. 21, 2015USD ($)

Dec. 31, 2014USD ($)

Mar. 04, 2014USD ($)

Business Acquisition [Line Items]

Amount of goodwill recognized

$ 7,112

$ 7,112

$ 7,501

Gain (loss) related to business divestiture

(9)

(29)

Impairment loss of assets held for sale

491

491

Broadcast Sports International, LLC [Member]

Business Acquisition [Line Items]

Sale of business, base sales price

$ 26

Gain (loss) related to business divestiture

$ (1)

(4)

Gain (loss) related to business divestiture after income taxes

(6)

MSI [Member]

Business Acquisition [Line Items]

Sale of business, base sales price

$ 318

€ 295

Estimated employee pension related liabilities | €

€ 60

Gain (loss) related to business divestiture

$ (4)

$ 4

4

Gain (loss) related to business divestiture after income taxes

8

Impairment loss of assets held for sale

$ 17

17

Impairment loss of assets held for sale after income taxes

12

Unrealized loss related to business divestiture after income taxes

3

MSI [Member] | Foreign Currency Forward Contracts [Member]

Business Acquisition [Line Items]

Gain (loss) related to business divestiture

1

Gain (loss) related to business divestiture after income taxes

$ 1

Forward contract to sell the estimated Euro proceeds | €

€ 285

Forward contract exchange rate | € / $

1.0782

Unrealized pre-tax loss related to business divestiture

$ 5

Tinsley Product Line [Member]

Business Acquisition [Line Items]

Sale of business, base sales price

$ 4

Gain (loss) related to business divestiture

$ (8)

$ (8)

Gain (loss) related to business divestiture after income taxes

$ (6)

ForceX, Inc. [Member]

Business Acquisition [Line Items]

Acquisition date

Oct. 13, 2015

ForceX, Inc. [Member] | Subsequent Event [Member]

Business Acquisition [Line Items]

Aggregate purchase price of acquisition

$ 60

MITEQ, Inc. [Member]

Business Acquisition [Line Items]

Aggregate purchase price of acquisition

$ 41

Acquisition date

Jan. 21, 2015

Amount of goodwill recognized

11

Goodwill deductible for income tax purposes

$ 4

Data Tactics Corporation [Member]

Business Acquisition [Line Items]

Aggregate purchase price of acquisition

$ 57

Acquisition date

Mar. 4, 2014

Amount of goodwill recognized

39

Goodwill deductible for income tax purposes

$ 39

CTC Aviation Group [Member]

Business Acquisition [Line Items]

Aggregate purchase price of acquisition

$ 236

£ 153

Acquisition date

May 27, 2015

Amount of goodwill recognized

$ 177

Acquisitions and Divestitures55

Acquisitions and Divestitures - Unaudited Pro Forma Statements of Operations Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Business Combinations [Abstract]
Pro forma net sales	$ 2,817	$ 2,973	$ 8,357	$ 9,021
Pro forma net (loss) income attributable to L-3	$ (299)	$ 156	$ (71)	$ 466
Pro forma diluted (loss) earnings per share	$ (3.74)	$ 1.80	$ (0.87)	$ 5.27

Acquisitions and Divestitures56

Acquisitions and Divestitures - Components of Loss of Business Divestitures Included in Statements of Operations (Detail) - USD ($) $ in Millions	May. 29, 2015	Sep. 25, 2015	Jun. 26, 2015	Mar. 27, 2015	Sep. 25, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gain (loss) related to the business divestitures		$ (9)			$ (29)
Non-cash impairment charge related to MSI assets held for sale		(491)			(491)
Tinsley Product Line [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gain (loss) related to the business divestitures		(8)			(8)
Broadcast Sports International, LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gain (loss) related to the business divestitures		$ (1)			(4)
MSI [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gain (loss) related to the business divestitures	$ (4)		$ 4		4
Non-cash impairment charge related to MSI assets held for sale				$ (17)	(17)
MSI [Member] | Foreign Currency Forward Contracts [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on a forward contract to sell Euro proceeds from MSI divestiture					$ (4)

Acquisitions and Divestitures57

Acquisitions and Divestitures - Schedule of Major Classes of Assets and Liabilities Included as Held for Sale (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Assets
Total current assets		$ 547
Total assets classified as held for sale		547
Liabilities
Total current liabilities		237
MSI [Member]
Assets
Cash and cash equivalents		61
Billed receivables, net of allowances of $6		77
Contracts in process		70
Inventories		70
Other current assets		10
Total current assets		288
Goodwill		231
Other assets		28
Total assets classified as held for sale		547
Liabilities
Accounts payable, trade		31
Accrued employment costs		22
Accrued expenses		33
Advance payments and billings in excess of costs incurred		55
Other current liabilities		21
Total current liabilities		162
Pension and postretirement benefits		56
Other liabilities		19
Total liabilities classified as held for sale		$ 237

Acquisitions and Divestitures58

Acquisitions and Divestitures - Schedule of Major Classes of Assets and Liabilities Included as Held for Sale (Parenthetical) (Detail) $ in Millions	Dec. 31, 2014USD ($)
MSI [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Billed receivables, allowances	$ 6

Acquisitions and Divestitures59

Acquisitions and Divestitures - Schedule of Net Sales and Income Before Income Taxes for MSI, BSI and Tinsley Product Line (Detail) - MSI, BSI and Tinsley Product Line [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	$ 1	$ 126	$ 201	$ 420
Income before income taxes	$ 1	$ 3	$ 2	$ 13

Contracts in Process - Componen

Contracts in Process - Components of Contracts in Process (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Components of contracts in process
Unbilled contract receivables, gross	$ 2,626	$ 2,280
Unliquidated progress payments	(1,057)	(887)
Unbilled contract receivables, net	1,569	1,393
Inventoried contract costs, gross	1,033	997
Unliquidated progress payments	(119)	(95)
Inventoried contract costs, net	914	902
Total contracts in process	$ 2,483	$ 2,295

Contracts in Process - General

Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Inventory Disclosure [Abstract]
Amounts included in inventoried contract costs at beginning of the period	$ 149	$ 146	$ 138	$ 133
Contract costs incurred:
IRAD and B&P	70	70	210	213
Other G&A	219	230	640	645
Total	289	300	850	858
Amounts charged to cost of sales	(269)	(300)	(819)	(845)
Amounts included in inventoried contract costs at end of the period	$ 169	$ 146	$ 169	$ 146

Contracts in Process - Selling,

Contracts in Process - Selling, General and Administrative Expenses and Research and Development Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Inventory Disclosure [Abstract]
Selling, general and administrative expenses	$ 53	$ 72	$ 198	$ 225
Research and development expenses	13	15	40	51
Total	$ 66	$ 87	$ 238	$ 276

Inventories - Inventories at Lo

Inventories - Inventories at Lower of Cost or Market (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials, components and sub-assemblies	$ 188	$ 127
Work in process	114	97
Finished goods	72	64
Total	$ 374	$ 288

Goodwill and Identifiable Int64

Goodwill and Identifiable Intangible Assets - Changes in Goodwill by Segment (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 25, 2015	Sep. 25, 2015
Goodwill [Line Items]
Balance, Beginning		$ 7,501
Business acquisitions		188
Business divestitures		(12)
Impairment charge	$ (491)	(491)
Foreign currency translation adjustments		(74)
Balance, Ending	7,112	7,112
Electronic Systems [Member]
Goodwill [Line Items]
Balance, Beginning		3,773
Business acquisitions		177
Business divestitures		$ (12)
Impairment charge
Foreign currency translation adjustments		$ (43)
Balance, Ending	3,895	3,895
Aerospace Systems [Member]
Goodwill [Line Items]
Balance, Beginning		$ 1,730
Business acquisitions
Business divestitures
Impairment charge
Foreign currency translation adjustments		$ (31)
Balance, Ending	1,699	1,699
Communication Systems [Member]
Goodwill [Line Items]
Balance, Beginning		992
Business acquisitions		$ 11
Business divestitures
Impairment charge
Foreign currency translation adjustments
Balance, Ending	1,003	$ 1,003
NSS [Member]
Goodwill [Line Items]
Balance, Beginning	1,006	$ 1,006
Business acquisitions
Business divestitures
Impairment charge	(491)	$ (491)
Foreign currency translation adjustments
Balance, Ending	$ 515	$ 515

Goodwill and Identifiable Int65

Goodwill and Identifiable Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 25, 2015	Sep. 25, 2015	Jun. 26, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill	$ 7,112	$ 7,112		$ 7,501
Goodwill, non-cash impairment charge	491	491
Accumulated goodwill impairment losses	549	549
NSS [Member]
Goodwill [Line Items]
Goodwill	515	515	$ 1,006	1,006
Goodwill, non-cash impairment charge	491	491
Goodwill, non-cash impairment charge after income taxes	463
Accumulated goodwill impairment losses	491	491
Electronic Systems [Member]
Goodwill [Line Items]
Goodwill	3,895	$ 3,895		3,773
Goodwill, non-cash impairment charge
Accumulated goodwill impairment losses	43	$ 43
Communication Systems [Member]
Goodwill [Line Items]
Goodwill	1,003	$ 1,003		$ 992
Goodwill, non-cash impairment charge
Accumulated goodwill impairment losses	$ 15	$ 15

Goodwill and Identifiable Int66

Goodwill and Identifiable Intangible Assets - Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	17 years
Gross Carrying Amount	$ 674	$ 632
Accumulated Amortization	418	389
Net Carrying Amount	$ 256	243
Customer Contractual Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	19 years
Gross Carrying Amount	$ 461	440
Accumulated Amortization	283	262
Net Carrying Amount	$ 178	178
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	11 years
Gross Carrying Amount	$ 186	165
Accumulated Amortization	118	111
Net Carrying Amount	$ 68	54
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	18 years
Gross Carrying Amount	$ 27	27
Accumulated Amortization	17	16
Net Carrying Amount	$ 10	$ 11

Goodwill and Identifiable Int67

Goodwill and Identifiable Intangible Assets - Amortization Expense (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization Expense	$ 10	$ 11	$ 29	$ 32

Goodwill and Identifiable Int68

Goodwill and Identifiable Intangible Assets - Estimated Amortization Expense (Detail) $ in Millions	Sep. 25, 2015USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Estimated amortization expense, 2015	$ 38
Estimated amortization expense, 2016	38
Estimated amortization expense, 2017	35
Estimated amortization expense, 2018	30
Estimated amortization expense, 2019	$ 27

Other Current Liabilities and69

Other Current Liabilities and Other Liabilities - Other Current Liabilities (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Other Current Liabilities:
Accruals for pending and threatened litigation (see Note 17)	$ 45	$ 38
Estimated costs in excess of estimated contract value to complete contracts in process in a loss position	79	75
Accrued product warranty costs	59	59
Accrued interest	52	46
Deferred revenues	29	30
Other	132	150
Total other current liabilities	$ 396	$ 398

Other Current Liabilities and70

Other Current Liabilities and Other Liabilities - Other Liabilities (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Other Liabilities:
Non-current income taxes payable (see Note 10)	$ 193	$ 196
Deferred compensation	45	43
Accrued workers' compensation	35	38
Accrued product warranty costs	34	34
Notes payable and capital lease obligations	9	1
Other	87	70
Total other liabilities	$ 403	$ 382

Other Current Liabilities and71

Other Current Liabilities and Other Liabilities - Changes in Company's Accrued Product Warranty Costs (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Accrued product warranty costs:
Balance at January 1	$ 93	$ 99
Acquisitions during the period	1
Accruals for product warranties issued during the period	46	$ 53
Settlements made during the period	(46)	(46)
Foreign currency translation adjustments	(1)	(1)
Balance at end of period	$ 93	$ 105

Debt - Components of Long-Term

Debt - Components of Long-Term Debt and Reconciliation to Carrying Amount of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Principal amount of long-term debt	$ 3,950	$ 3,950
Carrying amount of long-term debt	$ 3,940	$ 3,939
L-3 Communications Corporation [Member]
Debt Instrument [Line Items]
Borrowings under Amended and Restated Revolving Credit Facility
3.95% Senior Notes due 2016	$ 500	$ 500
1.50% Senior Notes due 2017	350	350
5.20% Senior Notes due 2019	1,000	1,000
4.75% Senior Notes due 2020	800	800
4.95% Senior Notes due 2021	650	650
3.95% Senior Notes due 2024	650	650
Carrying amount of long-term debt	3,940	3,939
L-3 Communications Holdings, Inc. [Member]
Debt Instrument [Line Items]
Unamortized discounts	(10)	(11)
Carrying amount of long-term debt	$ 3,940	$ 3,939

Debt - Components of Long-Ter73

Debt - Components of Long-Term Debt and Reconciliation to Carrying Amount of Long-Term Debt (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014	Sep. 25, 2015	Sep. 26, 2014
Debt Instrument [Line Items]
Repayments under the Credit Facility			$ 861	$ 1,367
Proceeds under the Credit Facility			861	$ 1,367
L-3 Communications Corporation [Member]
Debt Instrument [Line Items]
Repayments under the Credit Facility			861
Proceeds under the Credit Facility			861
Available borrowings under Credit Facility	$ 1,000		$ 1,000
L-3 Communications Corporation [Member] | 3.95% Senior Notes due 2016 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	3.95%	3.95%	3.95%
Debt instrument maturity period	2,016	2,016
L-3 Communications Corporation [Member] | 1.50% Senior Notes due 2017 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	1.50%	1.50%	1.50%
Debt instrument maturity period	2,017	2,017
L-3 Communications Corporation [Member] | 5.20% Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	5.20%	5.20%	5.20%
Debt instrument maturity period	2,019	2,019
L-3 Communications Corporation [Member] | 4.75% Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	4.75%	4.75%	4.75%
Debt instrument maturity period	2,020	2,020
L-3 Communications Corporation [Member] | 4.95% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	4.95%	4.95%	4.95%
Debt instrument maturity period	2,021	2,021
L-3 Communications Corporation [Member] | 3.95% Senior Notes due 2024 [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	3.95%	3.95%	3.95%
Debt instrument maturity period	2,024	2,024
Revolving Credit Facility [Member] | L-3 Communications Corporation [Member]
Debt Instrument [Line Items]
Revolving credit facility expiration date			Feb. 3, 2017

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 26, 2015	Sep. 25, 2015	Sep. 26, 2014	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Change in previously accrued income tax expense including interest and penalties		$ 10
Effective income tax rate excluding goodwill impairment charge and related income tax benefit		22.30%	29.50%
Anticipated decrease in unrecognized tax benefits over the next 12 months		$ 25
Effective income tax benefits	$ 36
Foreign tax benefits related to a legal restructuring	17
Resolution of outstanding income tax matters with U.S. and foreign tax authorities	10
Deferred tax benefits	$ 9	(21)	$ 91
Accrued potential interest included within non-current income taxes payable		18		$ 15
Accrued potential interest included within non-current income taxes payable, after income taxes		11		9
Potential penalties		$ 9		$ 9
NSS [Member]
Operating Loss Carryforwards [Line Items]
Marginal income tax rate on goodwill impairment charge		6.00%

Accumulated Other Comprehensi75

Accumulated Other Comprehensive (Loss) Income (AOCI) - Summary of Amounts Reclassified from AOCI into Net Income (Detail) - USD ($) $ in Millions	May. 29, 2015	Sep. 25, 2015	Jun. 26, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Beginning Balance					$ (584)	$ (110)
Other comprehensive loss before reclassifications, net of tax					(138)	(62)
Amounts reclassified from AOCI, net of tax					92	12
Total other comprehensive (loss) income		$ (52)		$ (64)	(46)	(50)
Ending Balance		(630)		(160)	(630)	(160)
Loss related to business divestitures		(9)			(29)
Cost of sales-products		(1,417)		(1,480)	(4,335)	(4,498)
(Loss) income before income taxes		(258)		215	24	667
Provision for income taxes		(38)		(58)	(87)	(197)
Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income		$ (14)		(2)	(92)	(12)
MSI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss related to business divestitures	$ (4)		$ 4		4
Foreign Currency Translation Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Beginning Balance					19	142
Other comprehensive loss before reclassifications, net of tax					(125)	$ (57)
Amounts reclassified from AOCI, net of tax					41
Total other comprehensive (loss) income					(84)	$ (57)
Ending Balance		$ (65)		85	(65)	85
Foreign Currency Translation Adjustment [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) income before income taxes					(41)
Net income					(41)
Foreign Currency Translation Adjustment [Member] | MSI [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss related to business divestitures					(41)
Unrealized (Losses) Gains on Hedging Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Beginning Balance					(5)	1
Other comprehensive loss before reclassifications, net of tax					(13)	(5)
Amounts reclassified from AOCI, net of tax					10	$ 5
Total other comprehensive (loss) income					(3)
Ending Balance		(8)		1	(8)	$ 1
Unrealized (Losses) Gains on Hedging Instruments [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) income before income taxes		(4)		1	(12)	(6)
Provision for income taxes				(1)	2	1
Net income		(4)			(10)	(5)
Unrealized (Losses) Gains on Hedging Instruments [Member] | MSI [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss related to business divestitures					(2)
Unrealized (Losses) Gains on Hedging Instruments [Member] | Other [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales-products		(4)		1	(10)	(6)
Amortization of Defined Benefit Pension Items [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net (loss) gain		(17)		(3)	(50)	(11)
(Loss) income before income taxes		(17)		(3)	(64)	(11)
Provision for income taxes		7		1	23	4
Net income		(10)		(2)	(41)	(7)
Amortization of Defined Benefit Pension Items [Member] | MSI [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss related to business divestitures					(14)
Unrecognized Losses and Prior Service Cost, Net [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Beginning Balance					$ (598)	$ (253)
Other comprehensive loss before reclassifications, net of tax
Amounts reclassified from AOCI, net of tax					$ 41	$ 7
Total other comprehensive (loss) income					41	7
Ending Balance		$ (557)		$ (246)	$ (557)	$ (246)

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($)	Jun. 10, 2015	Oct. 23, 2015	Sep. 25, 2015	Sep. 26, 2014	Dec. 04, 2014	Feb. 05, 2013
Class of Stock [Line Items]
Aggregate amount of repurchased shares			$ 605,000,000	$ 413,000,000
Remaining authorized amount of share repurchase programs			$ 940,000,000
Cash dividend declared per share	$ 0.65		$ 1.95	$ 1.80
Cash dividends			$ 163,000,000
Net reduction of accrued dividends through payment			$ 1,000,000
Dividend paid, record date			Aug. 17, 2015
Dividend paid date			Sep. 15, 2015
Treasury Stock [Member]
Class of Stock [Line Items]
Aggregate amount of repurchased shares			$ 605,000,000	$ 413,000,000
February 5, 2013 Share Repurchase Program [Member]
Class of Stock [Line Items]
Amount of shares authorized to be repurchased						$ 1,500,000,000
Average price per share of repurchased shares			$ 117.01
Aggregate amount of repurchased shares			$ 605,000,000
February 5, 2013 Share Repurchase Program [Member] | Treasury Stock [Member]
Class of Stock [Line Items]
Number of common shares repurchased			5,171,908
December 4, 2014 Share Repurchase Program [Member]
Class of Stock [Line Items]
Amount of shares authorized to be repurchased					$ 1,500,000,000
December 4, 2014 Share Repurchase Program [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Average price per share of repurchased shares		$ 106.70
Aggregate amount of repurchased shares		$ 75,000,000
December 4, 2014 Share Repurchase Program [Member] | Treasury Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Number of common shares repurchased		702,650

L-3 Holdings' Earnings (Loss)77

L-3 Holdings' Earnings (Loss) Per Common Share - Reconciliation of Basic and Diluted Earnings per Share (EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Reconciliation of net (loss) income:
Net (loss) income	$ (296)	$ 157	$ (63)	$ 470
Net income attributable to noncontrolling interests	(3)	(3)	(11)	(9)
Net (loss) income attributable to L-3 Holdings' common shareholders	$ (299)	$ 154	$ (74)	$ 461
Basic:
Weighted average common shares outstanding	80	85.1	81.5	85.7
Basic (loss) earnings per share:
Net (loss) income	$ (3.74)	$ 1.81	$ (0.91)	$ 5.38
Common and potential common shares:
Weighted average common shares outstanding	80	85.1	81.5	85.7
Assumed purchase of common shares for treasury		(2.9)		(3.2)
Assumed conversion of the CODES				1.1
Common and potential common shares	80	86.6	81.5	88.4
Diluted (loss) earnings per share:
Net (loss) income	$ (3.74)	$ 1.78	$ (0.91)	$ 5.21
Stock Options [Member]
Common and potential common shares:
Common and potential common shares		2.8		3
Unvested Restricted Stock Awards [Member]
Common and potential common shares:
Common and potential common shares		1.5		1.6
Performance Unit Awards [Member]
Common and potential common shares:
Common and potential common shares		0.1		0.1
Employee Stock Purchase Plan Contributions [Member]
Common and potential common shares:
Common and potential common shares				0.1

L-3 Holdings' Earnings (Loss)78

L-3 Holdings' Earnings (Loss) Per Common Share - Reconciliation of Basic and Diluted Earnings per Share (EPS) (Parenthetical) (Detail) - $ / shares shares in Millions	3 Months Ended	9 Months Ended
	Sep. 25, 2015	Sep. 25, 2015	Sep. 26, 2014	Jun. 18, 2014
Subsidiary, Sale of Stock [Line Items]
Incremental weighted average potential common shares	0	0
CODES Due 2035 [Member]
Subsidiary, Sale of Stock [Line Items]
Interest rate on debt instruments			3.00%
Debt instruments, maturity year		2,035
Conversion price of L-3 Holdings' CODES				$ 88.71
Debt instruments, retired date		Jun. 20, 2014

L-3 Holdings' Earnings (Loss)79

L-3 Holdings' Earnings (Loss) Per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Earnings Per Share [Abstract]
Shares excluded from computation of diluted earnings per share	4.5	0.6	4.5	0.5

Fair Value Measurements - Compa

Fair Value Measurements - Company's Assets and Liabilities at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Level 1 [Member]
Assets
Cash equivalents	$ 182	$ 416
Derivatives (foreign currency forward contracts)
Total assets	$ 182	$ 416
Liabilities
Derivatives (foreign currency forward contracts)
Level 2 [Member]
Assets
Cash equivalents
Derivatives (foreign currency forward contracts)	$ 2	$ 5
Total assets	2	5
Liabilities
Derivatives (foreign currency forward contracts)	$ 15	$ 11
Level 3 [Member]
Assets
Cash equivalents
Derivatives (foreign currency forward contracts)
Total assets
Liabilities
Derivatives (foreign currency forward contracts)

Financial Instruments - Carryin

Financial Instruments - Carrying Amounts and Estimated Fair Values of Company's Long-Term Debt and Foreign Currency Forward Contracts (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes, Carrying Amount	$ 3,940	$ 3,939
Senior Notes, Estimated Fair Value	4,068	4,178
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency forward contracts	(13)	(6)
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency forward contracts	$ (13)	$ (6)

Derivative Financial Instrume82

Derivative Financial Instruments - Notional Amounts of Company's Outstanding Foreign Currency Forward Contracts by Currency (Detail)	Sep. 25, 2015USD ($)
Derivative [Line Items]
Notional amounts of foreign currency forward contracts	$ 258,000,000
Canadian Dollar [Member]
Derivative [Line Items]
Notional amounts of foreign currency forward contracts	141,000,000
U.S. Dollar [Member]
Derivative [Line Items]
Notional amounts of foreign currency forward contracts	94,000,000
Euro [Member]
Derivative [Line Items]
Notional amounts of foreign currency forward contracts	21,000,000
British Pound [Member]
Derivative [Line Items]
Notional amounts of foreign currency forward contracts	$ 2,000,000

Derivative Financial Instrume83

Derivative Financial Instruments - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 25, 2015USD ($)
Derivative [Line Items]
Estimated net amount of existing losses expected to be reclassified into income within the next 12 months	$ 10
Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Foreign currency forward contracts, maturity year	2,018

Derivative Financial Instrume84

Derivative Financial Instruments - Location of Company's Derivative Instruments Recorded at Fair Value on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, liabilities	$ 13	$ 10
Other Current Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, liabilities	13	10
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, liabilities	2	1
Other Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, liabilities	2	1
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, assets	1	4
Other Current Assets [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, assets	1	4
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, assets	1	1
Other Assets [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Total derivative instruments, assets	$ 1	$ 1

Derivative Financial Instrume85

Derivative Financial Instruments - Location of Company's Derivative Instruments Recorded at Fair Value on Condensed Consolidated Balance Sheets (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities held for sale	$ 13	$ 10
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets held for sale	$ 1	4
Designated as Hedging Instruments [Member] | Other Current Liabilities [Member] | Assets Held for Sale [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities held for sale		2
Designated as Hedging Instruments [Member] | Other Current Assets [Member] | Assets Held for Sale [Member]
Derivatives, Fair Value [Line Items]
Derivative assets held for sale		$ 2

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) € in Millions, $ in Millions	Sep. 25, 2015USD ($)	Feb. 10, 2015USD ($)Plaintiff	Dec. 31, 2014USD ($)	Jul. 23, 2014EUR (€)	Sep. 28, 2012Plaintiff	Apr. 23, 2007Plaintiff	Oct. 31, 2015USD ($)Plaintiff	Sep. 25, 2015USD ($)Agreement	May. 31, 2012USD ($)	Mar. 09, 2010USD ($)
Contingencies And Commitments [Line Items]
Number of existing real estate lease agreements | Agreement								2
Real estate lease agreements, expiry date								Aug. 31, 2015
Lease, renewal term								5 years
Residual guarantee amount								$ 40
Increase in residual guarantee amount								17
Cash received from lessor at inception of new leases	$ 17							17
Aggregate liability in anticipation of a settlement	26							26
Recoveries from insurance contracts in connection with Bashkirian Airways	$ 11		$ 11
Number of plaintiffs re-filed their complaint against ACSS | Plaintiff						30
Compensatory damages									$ 48	$ 6.7
Number of plaintiffs released their claims against ACSS | Plaintiff					18
Number of plaintiffs settled their claims against ACSS | Plaintiff		12
Aggregate expenses incurred by plaintiff		$ 11
Award amount paid by insurer into escrow account								$ 11
Subsequent Event [Member]
Contingencies And Commitments [Line Items]
Aggregate payments made from escrow account							$ 7
Discount on litigation settlement							$ 0.1
Subsequent Event [Member] | Settled Litigation [Member]
Contingencies And Commitments [Line Items]
Number of plaintiffs settled their claims against ACSS | Plaintiff							8
Subsequent Event [Member] | Pending Litigation [Member]
Contingencies And Commitments [Line Items]
Number of plaintiffs settled their claims against ACSS | Plaintiff							4
Property Damages [Member]
Contingencies And Commitments [Line Items]
Claims for estimated damages | €				€ 11
Business Interruption [Member]
Contingencies And Commitments [Line Items]
Claims for estimated damages | €				€ 35

Pension and Other Postretirem87

Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	$ 29	$ 26	$ 93	$ 80
Interest cost	38	37	112	110
Expected return on plan assets	$ (51)	$ (48)	(155)	(145)
Amortization of prior service costs (credits)			1	1
Amortization of net loss (gain)	$ 17	$ 4	51	13
Curtailment loss	3		3	1
Net periodic benefit cost	$ 36	$ 19	105	$ 60
Postretirement Benefit Plans [Member]
Components of net periodic benefit cost:
Service cost		(2)	2
Interest cost	$ 1	4	5	$ 8
Expected return on plan assets	$ (1)	$ (1)	(3)	(3)
Amortization of prior service costs (credits)			$ (2)	(1)
Amortization of net loss (gain)		$ (1)		(2)
Curtailment loss		(1)		(1)
Net periodic benefit cost		$ (1)	$ 2	$ 1

Pension and Other Postretirem88

Pension and Other Postretirement Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 25, 2015USD ($)
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plans	$ 80
Expected contributions to plans during the remainder of fiscal year	18
Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plans	5
Expected contributions to plans during the remainder of fiscal year	$ 5

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail)	9 Months Ended
	Sep. 25, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price	$ 129.05
Stock options granted | shares	453,358
Expiration period of stock options granted from date of grant	10 years
Vesting period	3 years
Weighted average grant date fair value of stock options	$ 19.77
Unvested Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Units granted | shares	360,915
Weighted average grant date fair value	$ 128.84
Unvested Restricted Stock Awards [Member] | Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted | shares	41,138
Weighted average grant date fair value	$ 129.03
Length of service after grant date	3 years
Minimum payout range	0.00%
Maximum payout range	200.00%

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted Average Assumptions in Valuation Model (Detail) - Stock Options [Member]	9 Months Ended
	Sep. 25, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected holding period (in years)	5 years
Expected volatility	21.40%
Expected dividend yield	2.40%
Risk-free interest rate	1.50%

Supplemental Cash Flow Inform91

Supplemental Cash Flow Information - Supplemental Cash Flow Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Interest paid on outstanding debt	$ 127	$ 123
Income tax payments	114	116
Income tax refunds	$ 6	$ 8

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 25, 2015Segment
Segment Reporting [Abstract]
Number of reportable segments	4

Segment Information - Summary o

Segment Information - Summary of Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014	Dec. 31, 2014
Net Sales:
Net Sales	$ 2,817	$ 2,940	$ 8,323	$ 8,916
Operating Income (Loss):
Operating income	(214)	257	152	782
Loss related to business divestitures	(9)		(29)
Impairment charge	(491)		(491)
Depreciation and amortization:
Depreciation and amortization	$ 54	56	$ 164	165
Total Assets:
Assets held for sale					$ 547
Total Assets	$ 13,036		$ 13,036		13,836
Electronic Systems [Member]
Operating Income (Loss):
Impairment charge
Aerospace Systems [Member]
Operating Income (Loss):
Impairment charge
Communication Systems [Member]
Operating Income (Loss):
Impairment charge
NSS [Member]
Operating Income (Loss):
Impairment charge	(491)		$ (491)
Operating Segments [Member]
Operating Income (Loss):
Operating income	286	$ 257	672	$ 782
Loss related to business divestitures	(9)		(29)
Impairment charge	(491)		(491)
Operating Segments [Member] | Electronic Systems [Member]
Net Sales:
Net Sales	1,014	$ 1,128	3,113	$ 3,349
Operating Income (Loss):
Operating income	123	125	356	383
Depreciation and amortization:
Depreciation and amortization	26	30	81	89
Total Assets:
Total Assets	6,672		6,672		6,287
Operating Segments [Member] | Aerospace Systems [Member]
Net Sales:
Net Sales	1,068	1,037	3,092	3,173
Operating Income (Loss):
Operating income	103	64	148	196
Depreciation and amortization:
Depreciation and amortization	13	11	37	30
Total Assets:
Total Assets	3,103		3,103		3,011
Operating Segments [Member] | Communication Systems [Member]
Net Sales:
Net Sales	516	507	1,474	1,562
Operating Income (Loss):
Operating income	53	49	140	147
Depreciation and amortization:
Depreciation and amortization	12	13	37	38
Total Assets:
Total Assets	1,990		1,990		1,997
Operating Segments [Member] | NSS [Member]
Net Sales:
Net Sales	267	307	774	948
Operating Income (Loss):
Operating income	7	19	28	56
Depreciation and amortization:
Depreciation and amortization	3	2	9	8
Total Assets:
Total Assets	777		777		1,287
Corporate [Member]
Total Assets:
Total Assets	494		494		$ 707
Elimination of Intercompany Sales [Member]
Net Sales:
Net Sales	$ (48)	$ (39)	$ (130)	$ (116)

Employee Severance and Termin94

Employee Severance and Termination Costs - Additional Information (Detail) $ in Millions	Sep. 25, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 25, 2015USD ($)Employees	Sep. 26, 2014USD ($)	Sep. 25, 2015USD ($)Employees	Sep. 26, 2014USD ($)	Dec. 31, 2014USD ($)Employees
Restructuring and Related Activities [Abstract]
Employee severance and other termination costs			$ 4	$ 3	$ 10	$ 23	$ 30
Number of employees terminated | Employees			740		740		2,000
Remaining balance of employee termination costs	$ 6	$ 11

Employee Severance and Termin95

Employee Severance and Termination Costs - Employee Severance and Other Termination Costs Incurred by Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Employee severance and other termination costs	$ 4	$ 3	$ 10	$ 23	$ 30
Electronic Systems [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance and other termination costs	2		4	14
Aerospace Systems [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance and other termination costs	1	1	3	3
Communication Systems [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance and other termination costs	$ 1	$ 2	$ 3	5
NSS [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance and other termination costs				$ 1

Condensed Combining Financial96

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Additional Information (Detail)	Sep. 25, 2015
L-3 Communications Holdings, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Ownership percentage held in subsidiary	100.00%

Condensed Combining Financial97

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Balance Sheets (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014	Sep. 26, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 323	$ 442	$ 508	$ 500
Billed receivables, net	796	852
Contracts in process	2,483	2,295
Other current assets	693	601
Assets held for sale		547
Total current assets	4,295	4,737
Goodwill	7,112	7,501
Other assets	$ 1,629	$ 1,598
Investment in and amounts due from consolidated subsidiaries
Total assets	$ 13,036	$ 13,836
Current liabilities	$ 2,464	2,288
Liabilities held for sale		$ 237
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 1,973	$ 2,012
Long-term debt	3,940	3,939
Total liabilities	8,377	8,476
L-3 shareholders' equity	4,584	5,285
Noncontrolling interests	75	75
Total equity	4,659	5,360	$ 5,979	$ 6,056
Total liabilities and equity	13,036	13,836
L-3 Communications Holdings, Inc. [Member]
Current assets:
Cash and cash equivalents
Investment in and amounts due from consolidated subsidiaries	4,584	5,285
Total assets	4,584	5,285
Long-term debt	3,940	3,939
L-3 shareholders' equity	4,584	5,285
Total equity	4,584	5,285
Total liabilities and equity	4,584	5,285
L-3 Communications Corporation [Member]
Current assets:
Cash and cash equivalents	170	361	$ 330	$ 258
Billed receivables, net	260	320
Contracts in process	938	867
Other current assets	413	$ 365
Assets held for sale
Total current assets	1,781	$ 1,913
Goodwill	2,317	2,308
Other assets	800	817
Investment in and amounts due from consolidated subsidiaries	6,294	6,855
Total assets	11,192	11,893
Current liabilities	$ 931	$ 878
Liabilities held for sale
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 1,737	$ 1,791
Long-term debt	3,940	3,939
Total liabilities	6,608	6,608
L-3 shareholders' equity	$ 4,584	$ 5,285
Noncontrolling interests
Total equity	$ 4,584	$ 5,285
Total liabilities and equity	11,192	11,893
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	1	1	1
Billed receivables, net	318	329
Contracts in process	1,197	1,144
Other current assets	163	141
Assets held for sale		52
Total current assets	1,679	1,667
Goodwill	3,777	4,280
Other assets	552	576
Investment in and amounts due from consolidated subsidiaries	4,475	4,157
Total assets	10,483	10,680
Current liabilities	$ 1,044	1,017
Liabilities held for sale		$ 10
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 203	$ 190
Long-term debt
Total liabilities	$ 1,247	$ 1,217
L-3 shareholders' equity	$ 9,236	$ 9,463
Noncontrolling interests
Total equity	$ 9,236	$ 9,463
Total liabilities and equity	10,483	10,680
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	167	142	239	$ 261
Billed receivables, net	218	203
Contracts in process	348	284
Other current assets	117	95
Assets held for sale		495
Total current assets	850	1,219
Goodwill	1,018	913
Other assets	$ 277	$ 205
Investment in and amounts due from consolidated subsidiaries
Total assets	$ 2,145	$ 2,337
Current liabilities	504	455
Liabilities held for sale		227
Amounts due to consolidated subsidiaries	16	333
Other long-term liabilities	$ 33	$ 31
Long-term debt
Total liabilities	$ 553	$ 1,046
L-3 shareholders' equity	$ 1,592	$ 1,291
Noncontrolling interests
Total equity	$ 1,592	$ 1,291
Total liabilities and equity	2,145	2,337
Eliminations [Member]
Current assets:
Cash and cash equivalents	$ (15)	$ (62)	$ (62)	$ (19)
Billed receivables, net
Contracts in process
Other current assets
Assets held for sale
Total current assets	$ (15)	$ (62)
Goodwill
Other assets
Investment in and amounts due from consolidated subsidiaries	$ (15,353)	$ (16,297)
Total assets	(15,368)	(16,359)
Current liabilities	(15)	$ (62)
Liabilities held for sale
Amounts due to consolidated subsidiaries	$ (16)	$ (333)
Other long-term liabilities
Long-term debt
Total liabilities	$ (31)	$ (395)
L-3 shareholders' equity	(15,412)	(16,039)
Noncontrolling interests	75	75
Total equity	(15,337)	(15,964)
Total liabilities and equity	$ (15,368)	$ (16,359)

Condensed Combining Financial98

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Condensed Financial Statements, Captions [Line Items]
Total net sales	$ 2,817	$ 2,940	$ 8,323	$ 8,916
Total cost of sales	(2,531)	(2,683)	(7,651)	(8,134)
(Loss) gain related to business divestitures	(9)		(29)
Impairment charge	(491)		(491)
Operating (loss) income	(214)	257	152	782
Interest expense	(47)	(47)	(139)	(129)
Interest and other income, net	3	5	11	14
(Loss) income before income taxes	(258)	215	24	667
Benefit (provision) for income taxes	$ (38)	$ (58)	$ (87)	$ (197)
Equity in net (loss) income of consolidated subsidiaries
Net (loss) income	$ (296)	$ 157	$ (63)	$ 470
Net income attributable to noncontrolling interests	(3)	(3)	(11)	(9)
Net (loss) income attributable to L-3	(299)	154	(74)	461
Comprehensive income (loss) attributable to L-3	$ (351)	$ 90	$ (120)	$ 411
L-3 Communications Holdings, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Total net sales
Total cost of sales	$ (12)	$ (10)	$ (36)	$ (39)
(Loss) gain related to business divestitures
Impairment charge
Operating (loss) income	$ (12)	$ (10)	$ (36)	(39)
Interest expense				$ (2)
Interest and other income, net
(Loss) income before income taxes	$ (12)	$ (10)	$ (36)	$ (41)
Benefit (provision) for income taxes	7	3	11	12
Equity in net (loss) income of consolidated subsidiaries	(294)	161	(49)	490
Net (loss) income	$ (299)	$ 154	$ (74)	$ 461
Net income attributable to noncontrolling interests
Net (loss) income attributable to L-3	$ (299)	$ 154	$ (74)	$ 461
Comprehensive income (loss) attributable to L-3	(351)	90	(120)	411
L-3 Communications Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Total net sales	873	860	2,539	2,606
Total cost of sales	(790)	(787)	(2,313)	(2,354)
(Loss) gain related to business divestitures	$ (8)		$ (13)
Impairment charge
Operating (loss) income	$ 75	73	$ 213	252
Interest expense	(47)	(46)	(138)	(127)
Interest and other income, net	2	4	9	12
(Loss) income before income taxes	30	31	84	137
Benefit (provision) for income taxes	(10)	(8)	(19)	(41)
Equity in net (loss) income of consolidated subsidiaries	(319)	131	(139)	365
Net (loss) income	$ (299)	$ 154	$ (74)	$ 461
Net income attributable to noncontrolling interests
Net (loss) income attributable to L-3	$ (299)	$ 154	$ (74)	$ 461
Comprehensive income (loss) attributable to L-3	(351)	90	(120)	411
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Total net sales	1,584	1,628	4,574	4,908
Total cost of sales	(1,442)	(1,500)	(4,295)	(4,533)
(Loss) gain related to business divestitures	(1)		(29)
Impairment charge	(491)		(491)
Operating (loss) income	$ (350)	128	(241)	375
Interest expense		$ (2)	$ (1)	$ (2)
Interest and other income, net
(Loss) income before income taxes	$ (350)	$ 126	$ (242)	$ 373
Benefit (provision) for income taxes	$ (14)	$ (34)	$ (33)	$ (110)
Equity in net (loss) income of consolidated subsidiaries
Net (loss) income	$ (364)	$ 92	$ (275)	$ 263
Net income attributable to noncontrolling interests
Net (loss) income attributable to L-3	$ (364)	$ 92	$ (275)	$ 263
Comprehensive income (loss) attributable to L-3	(370)	89	(280)	264
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Total net sales	449	525	1,442	1,623
Total cost of sales	$ (388)	(469)	(1,275)	(1,468)
(Loss) gain related to business divestitures			$ 13
Impairment charge
Operating (loss) income	$ 61	56	$ 180	$ 155
Interest expense		1
Interest and other income, net	$ 1	1	$ 2	$ 2
(Loss) income before income taxes	62	58	182	157
Benefit (provision) for income taxes	$ (14)	$ (16)	$ (35)	$ (46)
Equity in net (loss) income of consolidated subsidiaries
Net (loss) income	$ 48	$ 42	$ 147	$ 111
Net income attributable to noncontrolling interests
Net (loss) income attributable to L-3	$ 48	$ 42	$ 147	$ 111
Comprehensive income (loss) attributable to L-3	(9)	(22)	73	53
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Total net sales	(89)	(73)	(232)	(221)
Total cost of sales	$ 101	83	$ 268	260
(Loss) gain related to business divestitures
Impairment charge
Operating (loss) income	$ 12	$ 10	$ 36	39
Interest expense				$ 2
Interest and other income, net
(Loss) income before income taxes	$ 12	$ 10	$ 36	$ 41
Benefit (provision) for income taxes	(7)	(3)	(11)	(12)
Equity in net (loss) income of consolidated subsidiaries	613	(292)	188	(855)
Net (loss) income	618	(285)	213	(826)
Net income attributable to noncontrolling interests	(3)	(3)	(11)	(9)
Net (loss) income attributable to L-3	615	(288)	202	(835)
Comprehensive income (loss) attributable to L-3	$ 730	$ (157)	$ 327	$ (728)

Condensed Combining Financial99

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Cash Flows (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014
Operating activities:
Net cash from operating activities	$ 631	$ 605
Investing activities:
Business acquisitions, net of cash acquired	(260)	$ (57)
Proceeds from sale of businesses, net of closing date cash balances	$ 308
Investments in L-3 Communications
Other investing activities	$ (134)	$ (105)
Net cash used in investing activities	(86)	(162)
Financing activities:
Proceeds from sale of Senior Notes		996
Retirement of CODES		(935)
Common stock repurchased	(605)	(413)
Dividends paid on L-3 Holdings' common stock	$ (163)	$ (158)
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	$ 57	$ 84
Net cash used in financing activities	(711)	(426)
Effect of foreign currency exchange rate changes on cash	(14)	(9)
Change in cash balance in assets held for sale	61
Net (decrease) increase in cash	(119)	8
Cash and cash equivalents, beginning of the period	442	500
Cash and cash equivalents, end of the period	323	508
L-3 Communications Holdings, Inc. [Member]
Operating activities:
Net cash from operating activities	768	$ 1,506
Investing activities:
Business acquisitions, net of cash acquired
Investments in L-3 Communications	(33)	$ (87)
Net cash used in investing activities	(33)	(87)
Financing activities:
Retirement of CODES		(935)
Common stock repurchased	(605)	(413)
Dividends paid on L-3 Holdings' common stock	(163)	(158)
Other financing activities	33	87
Net cash used in financing activities	(735)	$ (1,419)
Effect of foreign currency exchange rate changes on cash
Net (decrease) increase in cash
Cash and cash equivalents, beginning of the period
Cash and cash equivalents, end of the period
L-3 Communications Corporation [Member]
Operating activities:
Net cash from operating activities	337	$ 201
Investing activities:
Business acquisitions, net of cash acquired	(260)	$ (57)
Proceeds from sale of businesses, net of closing date cash balances	$ 4
Investments in L-3 Communications
Other investing activities	$ (63)	$ (37)
Net cash used in investing activities	$ (319)	(94)
Financing activities:
Proceeds from sale of Senior Notes		$ 996
Retirement of CODES
Common stock repurchased
Dividends paid on L-3 Holdings' common stock
Dividends paid to L-3 Holdings	$ (768)	$ (1,506)
Investments from L-3 Holdings	33	87
Other financing activities	526	388
Net cash used in financing activities	$ (209)	$ (35)
Effect of foreign currency exchange rate changes on cash
Change in cash balance in assets held for sale
Net (decrease) increase in cash	$ (191)	$ 72
Cash and cash equivalents, beginning of the period	361	258
Cash and cash equivalents, end of the period	170	330
Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	$ 348	$ 382
Investing activities:
Business acquisitions, net of cash acquired
Proceeds from sale of businesses, net of closing date cash balances	$ 27
Investments in L-3 Communications
Other investing activities	$ (45)	$ (52)
Net cash used in investing activities	$ (18)	$ (52)
Financing activities:
Proceeds from sale of Senior Notes
Retirement of CODES
Common stock repurchased
Dividends paid on L-3 Holdings' common stock
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	$ (331)	$ (329)
Net cash used in financing activities	$ (331)	$ (329)
Effect of foreign currency exchange rate changes on cash
Change in cash balance in assets held for sale	$ 1
Net (decrease) increase in cash		$ 1
Cash and cash equivalents, beginning of the period	$ 1
Cash and cash equivalents, end of the period	1	$ 1
Non-Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	$ 66	$ 69
Investing activities:
Business acquisitions, net of cash acquired
Proceeds from sale of businesses, net of closing date cash balances	$ 277
Investments in L-3 Communications
Other investing activities	$ (26)	$ (16)
Net cash used in investing activities	$ 251	$ (16)
Financing activities:
Proceeds from sale of Senior Notes
Retirement of CODES
Common stock repurchased
Dividends paid on L-3 Holdings' common stock
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	$ (338)	$ (66)
Net cash used in financing activities	(338)	(66)
Effect of foreign currency exchange rate changes on cash	(14)	(9)
Change in cash balance in assets held for sale	60
Net (decrease) increase in cash	25	(22)
Cash and cash equivalents, beginning of the period	142	261
Cash and cash equivalents, end of the period	167	239
Eliminations [Member]
Operating activities:
Net cash from operating activities	$ (888)	$ (1,553)
Investing activities:
Business acquisitions, net of cash acquired
Proceeds from sale of businesses, net of closing date cash balances
Investments in L-3 Communications	$ 33	$ 87
Other investing activities
Net cash used in investing activities	$ 33	$ 87
Financing activities:
Proceeds from sale of Senior Notes
Retirement of CODES
Common stock repurchased
Dividends paid on L-3 Holdings' common stock
Dividends paid to L-3 Holdings	$ 768	$ 1,506
Investments from L-3 Holdings	(33)	(87)
Other financing activities	167	4
Net cash used in financing activities	$ 902	$ 1,423
Effect of foreign currency exchange rate changes on cash
Change in cash balance in assets held for sale
Net (decrease) increase in cash	$ 47	$ (43)
Cash and cash equivalents, beginning of the period	(62)	(19)
Cash and cash equivalents, end of the period	$ (15)	$ (62)