L3 10-Q 10 Oct 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 27, 2014	Jul. 24, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	27-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Trading Symbol	'LLL	'
Entity Registrant Name	'L 3 COMMUNICATIONS HOLDINGS INC	'
Entity Central Index Key	'0001056239	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	85,010,528

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$299	$500
Billed receivables, net of allowances of $23 in 2014 and $26 in 2013	1,059	991
Contracts in process	2,633	2,431
Inventories	373	359
Deferred income taxes	145	147
Other current assets	196	166
Total current assets	4,705	4,594
Property, plant and equipment, net	1,033	1,042
Goodwill	7,838	7,796
Identifiable intangible assets	274	285
Deferred debt issue costs	30	24
Other assets	236	247
Total assets	14,116	13,988
Current liabilities:	'	'
Accounts payable, trade	553	541
Accrued employment costs	541	545
Accrued expenses	385	458
Advance payments and billings in excess of costs incurred	627	576
Income taxes	21	31
Other current liabilities	367	383
Total current liabilities	2,494	2,534
Pension and postretirement benefits	711	727
Deferred income taxes	599	635
Other liabilities	395	406
Long-term debt	3,938	3,630
Total liabilities	8,137	7,932
Commitments and contingencies (see Note 18)	'	'
L-3 shareholders' equity:	'	'
L-3 Communications Holdings, Inc.'s common stock: $.01 par value; 300,000,000 shares authorized, 85,274,892 shares outstanding at June 27, 2014 and 85,828,485 shares outstanding at December 31, 2013 (L-3 Communications Corporation's common stock: $.01 par value, 100 shares authorized, issued and outstanding)	5,694	5,653
L-3 Communications Holdings, Inc.'s treasury stock (at cost), 69,015,808 shares at June 27, 2014 and 66,118,406 shares at December 31, 2013	-5,621	-5,288
Retained earnings	5,927	5,726
Accumulated other comprehensive loss	-96	-110
Total L-3 shareholders' equity	5,904	5,981
Noncontrolling interests	75	75
Total equity	5,979	6,056
Total liabilities and equity	$14,116	$13,988

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Class of Stock [Line Items]	'	'
Net allowances for billed receivables	$23	$26
Treasury stock (at cost), shares	69,015,808	66,118,406
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	85,274,892	85,828,485
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

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Net sales:	'	'	'	'
Products	$1,698	$1,803	$3,347	$3,624
Services	1,321	1,386	2,629	2,762
Total net sales	3,019	3,189	5,976	6,386
Cost of sales:	'	'	'	'
Products	-1,552	-1,623	-3,018	-3,245
Services	-1,228	-1,276	-2,433	-2,541
Total cost of sales	-2,780	-2,899	-5,451	-5,786
Operating income	239	290	525	600
Interest expense	-39	-44	-82	-87
Interest and other income, net	4	7	9	10
Income before income taxes	204	253	452	523
Provision for income taxes	-63	-77	-139	-155
Net income	141	176	313	368
Net income attributable to noncontrolling interests	-4	-1	-6	-2
Net income attributable to L-3	$137	$175	$307	$366
Earnings per share attributable to L-3 Holdings' common shareholders:	'	'	'	'
Basic	$1.59	$1.95	$3.57	$4.06
Diluted	$1.53	$1.92	$3.43	$4.01
Cash dividends paid per common share	$0.60	$0.55	$1.20	$1.10
L-3 Holdings' weighted average common shares outstanding:	'	'	'	'
Basic	86.1	89.9	86.1	90.1
Diluted	89.3	91.1	89.4	91.3

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended				6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014		Jun. 28, 2013		Jun. 27, 2014		Jun. 28, 2013
Statement of Comprehensive Income [Abstract]	'		'		'		'
Net income	$141		$176		$313		$368
Other comprehensive income (loss):	'		'		'		'
Foreign currency translation adjustments	22		-18		6		-52
Unrealized gains (losses) on hedging instruments	8	[1]	-1	[1]	3	[1]	-4	[1]
Pension and postretirement benefit plans:	'		'		'		'
Amortization of net loss and prior service cost previously recognized	2	[2]	14	[2]	5	[2]	27	[2]
Total other comprehensive income (loss)	32		-5		14		-29
Comprehensive income	173		171		327		339
Comprehensive income attributable to noncontrolling interests	-4		-1		-6		-2
Comprehensive income attributable to L-3	$169		$170		$321		$337
[1]	Amounts are net of income taxes of $3 million and an income tax benefit of $1 million for the quarterly periods ended June 27, 2014 and June 28, 2013, respectively, and income taxes of $1 million and an income tax benefit of $2 million for the first half periods ended June 27, 2014 and June 28, 2013, respectively.
[2]	Amounts are net of income taxes of $2 million and $7 million for the quarterly periods ended June 27, 2014 and June 28, 2013, respectively, and income taxes of $3 million and $16 million for the first half periods ended June 27, 2014 and June 28, 2013, respectively.

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Income tax expense (benefit) on unrealized gains (losses) on hedging instruments	$3	($1)	$1	($2)
Income taxes on amortization of net loss and prior service cost previously recognized	$2	$7	$3	$16

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
In Millions, except Share data, unless otherwise specified
Beginning Balance at Dec. 31, 2012	$5,527	$1	$5,313	($4,488)	$5,175	($550)	$76
Beginning Balance, Shares at Dec. 31, 2012	'	90,400,000	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'	'	'
Net income	368	'	'	'	366	'	2
Other comprehensive income	-29	'	'	'	'	-29	'
Distributions to noncontrolling interests	-4	'	'	'	'	'	-4
Cash dividends paid on common stock	-99	'	'	'	-99	'	'
Shares issued:	'	'	'	'	'	'	'
Employee savings plans	68	'	68	'	'	'	'
Employee savings plans, Shares	'	900,000	'	'	'	'	'
Exercise of stock options	31	'	31	'	'	'	'
Exercise of stock options, Shares	'	500,000	'	'	'	'	'
Employee stock purchase plan	18	'	18	'	'	'	'
Employee stock purchase plan, Shares	'	300,000	'	'	'	'	'
Stock-based compensation expense	28	'	28	'	'	'	'
Treasury stock purchased	-248	'	'	-248	'	'	'
Treasury stock purchased, Shares	'	-3,100,000	'	'	'	'	'
Other	-10	'	-8	'	-2	'	'
Other, Shares	'	400,000	'	'	'	'	'
Ending Balance at Jun. 28, 2013	5,650	1	5,450	-4,736	5,440	-579	74
Ending Balance, Shares at Jun. 28, 2013	'	89,400,000	'	'	'	'	'
Beginning Balance at Dec. 31, 2013	6,056	1	5,652	-5,288	5,726	-110	75
Beginning Balance, Shares at Dec. 31, 2013	'	85,800,000	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'	'	'
Net income	313	'	'	'	307	'	6
Other comprehensive income	14	'	'	'	'	14	'
Distributions to noncontrolling interests	-6	'	'	'	'	'	-6
Cash dividends paid on common stock	-104	'	'	'	-104	'	'
Shares issued:	'	'	'	'	'	'	'
Employee savings plans	74	'	74	'	'	'	'
Employee savings plans, Shares	'	700,000	'	'	'	'	'
Exercise of stock options	101	'	101	'	'	'	'
Exercise of stock options, Shares	'	1,100,000	'	'	'	'	'
Employee stock purchase plan	18	'	18	'	'	'	'
Employee stock purchase plan, Shares	'	200,000	'	'	'	'	'
Stock-based compensation expense	29	'	29	'	'	'	'
Treasury stock purchased	-333	'	'	-333	'	'	'
Treasury stock purchased, Shares	'	-2,900,000	'	'	'	'	'
Retirement of Convertible Contingent Debt Securities	-160	'	-160	'	'	'	'
Other	-23	'	-21	'	-2	'	'
Other, Shares	'	400,000	'	'	'	'	'
Ending Balance at Jun. 27, 2014	$5,979	$1	$5,693	($5,621)	$5,927	($96)	$75
Ending Balance, Shares at Jun. 27, 2014	'	85,300,000	'	'	'	'	'

Consolidated_Statements_of_Equ1

Consolidated Statements of Equity (Parenthetical) (USD $)	6 Months Ended
	Jun. 27, 2014	Jun. 28, 2013
Class of Stock [Line Items]	'	'
Cash dividends paid on common stock, per share	$1.20	$1.10
Retained Earnings [Member]	'	'
Class of Stock [Line Items]	'	'
Cash dividends paid on common stock, per share	$1.20	$1.10

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Operating activities:	'	'
Net income	$313	$368
Depreciation of property, plant and equipment	84	81
Amortization of intangibles and other assets	25	25
Deferred income tax provision	43	8
Stock-based employee compensation expense	29	28
Contributions to employee savings plans in L-3 Holdings' common stock	74	61
Amortization of pension and postretirement benefit plans net loss and prior service cost	8	43
Amortization of bond discounts and deferred debt issue costs (included in interest expense)	3	3
Other non-cash items	-4	'
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:	'	'
Billed receivables	-61	-76
Contracts in process	-195	-51
Inventories	-14	-17
Other assets	8	-46
Accounts payable, trade	8	38
Accrued employment costs	-3	27
Accrued expenses	-71	-70
Advance payments and billings in excess of costs incurred	49	-41
Income taxes	-1	25
Excess income tax benefits related to share-based payment arrangements	-16	-2
Other current liabilities	-17	'
Pension and postretirement benefits	-16	3
All other operating activities	-31	-11
Net cash from operating activities	215	396
Investing activities:	'	'
Business acquisitions, net of cash acquired	-57	-1
Proceeds from the sale of a business and product line	5	4
Capital expenditures	-67	-110
Dispositions of property, plant and equipment	2	9
Other investing activities	'	-6
Net cash used in investing activities	-117	-104
Financing activities:	'	'
Proceeds from sale of senior notes	996	'
Retirement of CODES	-935	'
Borrowings under revolving credit facility	1,031	994
Repayment of borrowings under revolving credit facility	-1,031	-994
Common stock repurchased	-333	-248
Dividends paid on L-3 Holdings' common stock	-107	-101
Proceeds from exercises of stock options	86	33
Proceeds from employee stock purchase plan	18	18
Excess income tax benefits related to share-based payment arrangements	16	2
Debt issue costs	-8	'
Other financing activities	-32	-8
Net cash used in financing activities	-299	-304
Effect of foreign currency exchange rate changes on cash and cash equivalents	'	-9
Net decrease in cash and cash equivalents	-201	-21
Cash and cash equivalents, beginning of the period	500	349
Cash and cash equivalents, end of the period	$299	$328

Description_of_Business

Description of Business	6 Months Ended
	Jun. 27, 2014
Accounting Policies [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 aerospace systems and national security solutions. 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), U.S. Department of State (DoS), allied international governments, and domestic and international commercial customers.
	In the first quarter of 2014, the Company completed a realignment of its segments to better align its organizational structure with customer priorities and increase operational efficiencies. As a result of the realignment, L-3’s structure consists of four segments: (1) Aerospace Systems, (2) Electronic Systems, (3) Communication Systems and (4) National Security Solutions (NSS). Aerospace Systems delivers integrated solutions for the global Intelligence, Surveillance and Reconnaissance (ISR) market and provides modernization, upgrade, sustainment, and maintenance and logistics support for a wide variety of aircraft and ground systems. 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, power & propulsion systems, sensor systems, marine systems international, aviation products, warrior systems and security & detection. 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 information technology (IT) services, analytics and intelligence analysis to the DoD, U.S. Government intelligence agencies, federal civilian agencies and allied international governments.
	Financial information with respect to the Company’s segments is included in Note 22 to the unaudited condensed consolidated financial statements and Note 23 to the audited consolidated financial statements included in its Form 10-K/A. Financial information for the quarterly and six month (first half) periods ended June 28, 2013 in these unaudited condensed consolidated financial statements has been revised for the segment realignment discussed above.

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 27, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	2.  Basis of Presentation
	These unaudited condensed consolidated financial statements for the quarterly and first half periods ended June 27, 2014 should be read in conjunction with the audited consolidated financial statements of L-3 Holdings and L-3 Communications included in their Form 10-K/A filed October 10, 2014.
	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 of L-3 Communications and (2) its guarantee of other contractual obligations of L-3 Communications and its subsidiaries. As of the date of this report, L-3 Holdings’ obligation for its 3% Convertible Contingent Debt Securities (CODES) due 2035, which were issued by on July 29, 2005, have been fully retired. See Note 10 to these unaudited financial statements. L-3 Holdings’ obligations relating to the CODES were jointly, severally, fully and unconditionally guaranteed by L-3 Communications and certain of its wholly-owned domestic subsidiaries. Accordingly, such debt was reflected as debt of L-3 Communications in its consolidated financial statements at December 31, 2013 in accordance with the accounting standards for pushdown accounting. All issuances of and conversions into L-3 Holdings’ equity securities, including grants of stock options, restricted stock, 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 24 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, 2013 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 presentation 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 nearest to 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.
	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 47% of the Company’s net sales in 2013 were accounted for under contract accounting standards, of which approximately 38% were fixed-price type contracts and approximately 9% were cost-plus type contracts. For contracts 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 to 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 increased consolidated operating income by $45 million, or 9%, for the first half period ended June 27, 2014 and $54 million, or 9%, for the first half period ended June 28, 2013.
	For a more complete discussion of these estimates and assumptions, see the Form 10-K/A filed on October 10, 2014.

Revisions_to_Previously_Issued

Revisions to Previously Issued Financial Statements	6 Months Ended
	Jun. 27, 2014
Accounting Changes and Error Corrections [Abstract]	'
Revisions to Previously Issued Financial Statements	'
	3.  Revisions to Previously Issued Financial Statements
	The Company is revising its previously issued financial statements to update for: (1) accounting adjustments due to the internal review at its Aerospace Systems segment, (2) accounting related to a sales-type lease transaction for flight simulator systems within its Electronic Systems segment, and (3) previously identified immaterial errors already recognized in its financial statements but not recorded in the appropriate periods. The accounting errors related to the sales-type lease transaction and immaterial out of period amounts are not related to the internal review at its Aerospace Systems segment.
	Internal Review of Aerospace Systems Segment: The Company conducted an internal review related to instances of misconduct and accounting errors at its Aerospace Systems segment. This review was conducted with the assistance of outside legal and accounting advisors, and has been completed. As a result of the internal review, the Company identified and recorded aggregate pre-tax charges as follows: (1) $60 million for 2013, (2) $25 million for 2012, (3) $5 million for 2011, and (4) $4 million for periods prior to 2011. Furthermore, this Form 10-Q and the Form 10-Q/A also include aggregate pre-tax charges related to the internal review of the Aerospace Systems segment. The pre-tax charge related to the internal review of the Aerospace Systems segment for the three months ended March 28, 2014 is approximately $20 million, and for the three months ended June 27, 2014 is approximately $55 million.
	The adjustments related to the internal review only affected the Logistics Solutions and Platform Systems sectors of the Aerospace Systems segment. The cumulative aggregate adjustments attributable to the Logistics Solutions sector are approximately $117 million, and at the Platform Systems sector are approximately $52 million through June 27, 2014. The Logistics Solutions sector adjustments relate to: (1) losses of $69 million with respect to the U.S. Army C-12 fixed-price maintenance and logistics support contract due to cost overruns inappropriately deferred, sales invoices inappropriately prepared, and the failure to timely and accurately perform contract estimates at completion and valuation assessments of inventories and receivables, at the Army Sustainment Division, and (2) accounting errors of $48 million in connection with the valuation of inventories and receivables as well as the correction for certain accruals on other logistics support contracts. The Platform Systems sector adjustments are primarily due to: (1) losses of $37 million on two aircraft modification contracts and two contracts for rotary wing sub-assemblies and parts, and (2) write-offs of deferred costs of $15 million to design and test aerostructures for a new commercial aircraft.
	Sales-Type Lease Transaction: The Company routinely performs on-site accounting and internal control review procedures on a rotational basis. As part of a previously planned review of the Simulation & Training business in its Electronic Systems segment and unrelated to the internal review at its Aerospace Systems segment, the Company evaluated the accounting treatment related to a sales-type lease transaction with the U.S. Army for rotary wing flight simulator systems. The period of performance under this contract began in 2004 and ends in 2023. Based on the results of this evaluation, the Company has adjusted its previously issued financial statements to: (1) increase interest income accretion on the net investment related to this sales-type lease transaction by an estimated aggregate amount of approximately $5 million for 2013, $3 million for each of 2012 and 2011, and $12 million for periods prior to 2011 and (2) decrease sales by approximately $8 million for 2014 and $7 million for 2013 and related decrease in cost of sales by approximately $7 million for each of 2014 and 2013 and $5 million for periods prior to 2011.
	Out of Period Amounts: The Company identified various out of period amounts included in its previously issued financial statements that were deemed to be immaterial individually and in the aggregate. In prior periods, in accordance with Accounting Standards Codification (“ASC”) 650-10-S99 and S55 (formerly Staff Accounting Bulletins (“SAB”) No. 99 and No. 108), Accounting Changes and Error Corrections, the Company concluded that these errors were, individually, and in the aggregate, not material, quantitatively or qualitatively, to the financial statements in the period recorded or to the relevant prior periods. Accordingly, the Company recorded these errors in the financial statements in the period that the error was identified. The Company, on a voluntary basis, is revising its previously issued financial statements to correct for these errors already recognized in its financial statements but not recorded in the appropriate periods to reflect them in the appropriate period. These out of period amounts were not discovered as part of the internal review of the Aerospace Systems segment discussed above, but rather represent previously identified errors “resulting from mathematical mistakes, mistakes in application of generally accepted accounting principles, or oversight or misuse of facts that existed at the time the financial statements were prepared,” as defined in ASC 250-10-20 Accounting Changes and Error Corrections. The Company, therefore, is not treating these amounts as changes in estimates. These errors consist of: (1) increases in development and material costs related to Broadband Communication Systems that were recorded in the first quarter of 2013 but should have been recorded in the fourth quarter of 2012, (2) a sub-contractor subscription deposit that was recorded as sales and income in the fourth quarter of 2012 but should have been amortized to sales and income during 2013, (3) costs accrued in the fourth quarter of 2012 for goods or services received in the first quarter of 2013, (4) several unrecorded liabilities that were recorded in the first quarter of 2013 but should have been recorded in the fourth quarter of 2012, (5) a correction of accrued vacation that was recorded in the fourth quarter of 2013 but should have been recorded in the fourth quarter of 2012 and the first, second and third quarters of 2013, and (6) a warranty reserve reduction recorded in the third quarter of 2012 that should have been recorded in the fourth quarter of 2011.
	With respect to each of these immaterial out of period amounts included in the Company’s previously issued financial statements, the table below presents the: (1) nature of the adjustments, (2) applicable segment and (3) amount of increase (or decrease) to sales and operating income for the quarters ended December 31, September 27, June 28, and March 29, 2013.
					December 31,								September 27,								June 28,								March 29,
					2013								2013								2013								2013
	Nature of Adjustment		Applicable		Sales				Operating				Sales				Operating				Sales				Operating				Sales				Operating
			Segment						Income								Income								Income								Income
					($ in millions)
	Higher development and material costs for networked communications systems		Communication Systems		$	—			$	—			$	—			$	—			$	—			$	—			$	10			$	10
	Sub-contractor subscription deposit		Aerospace Systems			5				—				7				1				7				1				7				1
	Costs accruals for goods/services received		Aerospace Systems			—				—				—				—				—				—				5				1
	Unrecorded liabilities		Aerospace Systems			—				—				—				—				—				—				(2	)			—
	Accrued vacation		Aerospace Systems			—				6				—				(2	)			—				(2	)			—				(2	)
	Overstated revenue		Aerospace Systems			4				—				(4	)			—				—				—				—				—
	Warranty reserve		Electronic Systems			—				—				—				—				—				—				—				—
	Total				$	9			$	6			$	3			$	(1	)		$	7			$	(1	)		$	20			$	10
	The table below presents the impact of the matters discussed above on sales and pre-tax income in total, for the six month period ended June 27, 2014, years ended December 31, 2013, 2012, and 2011, and for the years ended prior to December 31, 2011.
			Total								Six Months								2013								2012								2011						Prior to 2011
											2014
			Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales			Pre-tax			Sales			Pre-tax
							Income								Income								Income								Income							Income						Income
			(in millions)
	Army C-12 Contract		$	(32	)		$	(69	)		$	(3	)		$	(15	)		$	(25	)		$	(35	)		$	(3	)		$	(16	)		$	(1	)	$	(3	)	$	—		$	—
	Other Logistics Support Contracts			(5	)			(48	)			—				(20	)			(2	)			(11	)			(2	)			(11	)			—			(2	)		(1	)		(4	)
	Logistics Solutions			(37	)			(117	)			(3	)			(35	)			(27	)			(46	)			(5	)			(27	)			(1	)		(5	)		(1	)		(4	)
	Platform Systems			(21	)			(52	)			(12	)			(40	)			(12	)			(14	)			3				2				—			—			—			—
	Total Internal Review of Aerospace Systems Segment			(58	)			(169	)			(15	)			(75	)			(39	)			(60	)			(2	)			(25	)			(1	)		(5	)		(1	)		(4	)
	Sales-Type Lease Transaction			(15	)			29				(8	)			1				(7	)			5				—				3				—			3			—			17
	Out of Period Amounts			—				—				—				—				39				14				(36	)			(18	)			(3	)		4			—			—
	Total Revisions		$	(73	)		$	(140	)		$	(23	)		$	(74	)		$	(7	)		$	(41	)		$	(38	)		$	(40	)		$	(4	)	$	2		$	(1	)	$	13
	The table below presents the impact of the matters discussed above on sales and pre-tax income for the quarters ended June 27 and March 28, 2014, December 31, September 27, June 28, 2013 and March 29, 2013.
			June 27,								March 28,								December 31,								September 27,								June 28,						March 29,
			2014								2014								2013								2013								2013						2013
			Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales			Pre-tax			Sales			Pre-tax
							Income								Income								Income								Income							Income						Income
			(in millions)
	Army C-12 Contract		$	(1	)		$	(11	)		$	(2	)		$	(4	)		$	(24	)		$	(20	)		$	3			$	(2	)		$	(3	)	$	(7	)	$	(1	)	$	(6	)
	Other Logistics Support Contracts			—				(15	)			—				(5	)			(1	)			(2	)			(1	)			(5	)			—			(2	)		—			(2	)
	Logistics Solutions			(1	)			(26	)			(2	)			(9	)			(25	)			(22	)			2				(7	)			(3	)		(9	)		(1	)		(8	)
	Platform Systems			(6	)			(29	)			(6	)			(11	)			(2	)			(2	)			1				—				(6	)		(6	)		(5	)		(6	)
	Total Internal Review of Aerospace			(7	)			(55	)			(8	)			(20	)			(27	)			(24	)			3				(7	)			(9	)		(15	)		(6	)		(14	)
	Systems Segment
	Sales-Type Lease Transaction			(3	)			1				(5	)			—				(3	)			1				(1	)			2				(1	)		1			(2	)		1
	Out of Period Amounts			—				—				—				—				9				6				3				(1	)			7			(1	)		20			10
	Total Revisions		$	(10	)		$	(54	)		$	(13	)		$	(20	)		$	(21	)		$	(17	)		$	5			$	(6	)		$	(3	)	$	(15	)	$	12		$	(3	)
	In accordance with ASC 650-10-S99 and S55, the Company performed an analysis to determine if the impact of the amounts disclosed above were material to its previously issued financial statements. Based on that analysis, the Company believes that its previously issued financial statements are not materially misstated on either a quantitative or qualitative basis. However, as a result of completing the review, the Company believes that correcting these errors in this quarterly report on Form 10-Q would, in the aggregate, cause a material misstatement to forecasted pre-tax income and net income for the fiscal year ending December 31, 2014. Accordingly, the Company is correcting these errors by revising its previously issued financial statements to record all the adjustments in the tables above in the appropriate period.
	The tables below present the Company’s: (1) As Previously Reported, (2) Adjustments, and (3) As Currently Reported Condensed Consolidated Statements of Operations for the quarterly and first half periods ended June 28, 2013 and the Operating Activities for the Statement of Cash Flows for the first half period ended June 28, 2013. The Adjustments correct for: (1) the results of the Aerospace Systems internal review, (2) the accounting related to a sales-type lease transaction within the Company’s Electronic Systems segment and (3) immaterial out of period amounts previously recorded in the Company’s financial statements but not recorded in the appropriate period to reflect them in the appropriate period.
							Adjustments for:
			As				Aerospace				Sales- Type				Out of Period				As
			Previously				Systems				Lease				Amounts				Revised
			Reported				Segment				Transaction
							Internal
							Review
			(in millions, except per share data)
	Unaudited Condensed Consolidated Statement of Operations, for the second quarter ended June 28, 2013:
	Net sales:
	Products		$	1,810			$	(6	)		$	(1	)		$	—			$	1,803
	Services			1,382				(3	)			—				7				1,386
	Total net sales			3,192				(9	)			(1	)			7				3,189
Cost of sales:
Products			(1,623	)			(1	)			2				(1	)			(1,623	)
Services			(1,262	)			(6	)			—				(8	)			(1,276	)
Total cost of sales			(2,885	)			(7	)			2				(9	)			(2,899	)
Operating income			307				(16	)			1				(2	)(1)			290
Interest expense			(44	)			—				—				—				(44	)
Interest and other income, net			5				—				1				1				7
Income before income taxes			268				(16	)			2				(1	)			253
Provision for income taxes			(82	)			6				(1	)			—				(77	)
Net income		$	186			$	(10	)		$	1			$	(1	)		$	176
Net income attributable to noncontrolling interests			(1	)			—				—				—				(1	)
Net income attributable to L-3		$	185			$	(10	)		$	1			$	(1	)		$	175
Earnings per share attributable to L-3 Holdings’ common shareholders:
Basic		$	2.06			$	(0.11	)		$	0.01			$	(0.01	)		$	1.95
Diluted		$	2.03			$	(0.11	)		$	0.01			$	(0.01	)		$	1.92
Cash dividends paid per common share		$	0.55			$	—			$	—			$	—			$	0.55
L-3 Holdings’ weighted average common shares outstanding:
Basic			89.9				—				—				—				89.9
Diluted			91.1				—				—				—				91.1
-1	Includes rounding of $1 million.
						Adjustments for:
		As				Aerospace				Sales- Type				Out of Period				As
		Previously				Systems				Lease				Amounts				Revised
		Reported				Segment				Transaction
						Internal
						Review
		(in millions, except per share data)
Unaudited Condensed Consolidated Statement of Operations, for the first half ended June 28, 2013:
Net sales:
Products		$	3,623			$	(10	)		$	(3	)		$	14			$	3,624
Services			2,754				(4	)			—				12				2,762
Total net sales			6,377				(14	)			(3	)			26				6,386
Cost of sales:
Products			(3,243	)			(2	)			4				(4	)			(3,245	)
Services			(2,514	)			(13	)			—				(14	)			(2,541	)
Total cost of sales			(5,757	)			(15	)			4				(18	)			(5,786	)
Operating income			620				(29	)			1				8				600
Interest expense			(87	)			—				—				—				(87	)
Interest and other income, net			8				—				2				—				10
Income before income taxes			541				(29	)			3				8				523
Provision for income taxes			(161	)			10				(1	)			(3	)			(155	)
Net income		$	380			$	(19	)		$	2			$	5			$	368
Net income attributable to noncontrolling interests			(2	)			—				—				—				(2	)
Net income attributable to L-3		$	378			$	(19	)		$	2			$	5			$	366
Earnings per share attributable to L-3 Holdings’ common shareholders:
Basic		$	4.2			$	(0.21	)		$	0.02			$	0.05			$	4.06
Diluted		$	4.14			$	(0.20	)		$	0.02			$	0.05			$	4.01
Cash dividends paid per common share		$	1.1			$	—			$	—			$	—			$	1.1
L-3 Holdings’ weighted average common shares outstanding:
Basic			90.1				—				—				—				90.1
Diluted			91.3				—				—				—				91.3
		As				Net				As
		Previously				Adjustments				Revised
		Reported
		(in millions)
Unaudited Consolidated Statement of Cash Flows for first half ended June 28, 2013:
Operating activities:
Net income		$	380			$	(12	)		$	368
Depreciation of property, plant and equipment			81				—				81
Amortization of intangibles and other assets			25				—				25
Deferred income tax provision			13				(5	)			8
Stock-based employee compensation expense			28				—				28
Contributions to employee savings plans in L-3 Holdings’ common stock			61				—				61
Amortization of pension and postretirement benefit plans net loss and prior service cost			43				—				43
Amortization of bond discounts and deferred debt issue costs (included in interest expense)			3				—				3
Other non-cash items			—				—				—
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:
Billed receivables			(76	)			—				(76	)
Contracts in process			(10	)			(41	)			(51	)
Inventories			(17	)			—				(17	)
Other assets			(44	)			(2	)			(46	)
Accounts payable, trade			50				(12	)			38
Accrued employment costs			20				7				27
Accrued expenses			(64	)			(6	)			(70	)
Advance payments and billings in excess of costs incurred			(89	)			48				(41	)
Income taxes			27				(2	)			25
Excess income tax benefits related to share-based payment arrangements			(2	)			—				(2	)
Other current liabilities			(3	)			3				—
Pension and postretirement benefits			3				—				3
All other operating activities			(33	)			22				(11	)
Net cash (used in) from operating activities		$	396			$	—			$	396

Recently_Issued_Accounting_Sta

Recently Issued Accounting Standards	6 Months Ended
	Jun. 27, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recently Issued Accounting Standards	'
	4.  Recently Issued Accounting Standards
	Effective January 1, 2014, the Company adopted Financial Accounting Standards Board (FASB) issued amendments to an accounting standard that require an unrecognized tax benefit or portion of an unrecognized tax benefit to be presented as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except when certain conditions exist. The adoption of this standard did not impact the Company’s financial position, results of operations or cash flows.
	In June 2014, the FASB issued Accounting Standard Update (ASU) 2014-12, which provides new guidance on accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period. The update requires a reporting entity to treat a performance target that affects vesting and that could be achieved after the requisite service period as a performance condition under Accounting Standards Codification Topic (ASC) 718 Compensation — Stock Compensation, and apply existing guidance as it relates to awards with performance conditions that affect vesting to account for such awards. The update is effective for the Company for the interim and annual periods beginning after December 15, 2015. The Company is currently evaluating the impact of the adoption of this standard, if any, on our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. One of the core principles of the new standard is that a company should recognize revenue based on the satisfaction of performance obligations, which depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard will be effective for the Company for interim and annual reporting periods beginning January 1, 2017. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company is currently evaluating the expected impact of the adoption of this standard on our consolidated financial statements and the transition alternatives available.
	In April 2014, the FASB issued an accounting standards update that provides new guidance on the accounting and reporting of discontinued operations. Under the new guidance, only disposals representing a strategic shift in operations should be presented as discontinued operations. Those strategic shifts should have a major effect on the organization’s operations and financial results. Additionally, the new guidance requires additional disclosures about discontinued operations. The update is effective for the Company for interim and annual periods beginning January 1, 2015. The adoption of this standard is not expected to impact the Company’s financial position, results of operations or cash flows and will only affect the treatment of future discontinued operations.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 27, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	5.  Acquisitions
	The business acquisitions discussed below are included in the Company’s results of operations from their respective dates of acquisition.
	2014 Business Acquisition
	On March 4, 2014, the Company acquired Data Tactics Corporation, renamed L-3 Data Tactics, for a purchase price of $57 million, which was financed with cash on hand. The purchase price is subject to adjustment based on closing date net working capital. L-3 Data Tactics is a specialized provider of large-scale data analytics, cybersecurity and cloud computing solution services, primarily to the DoD. Based on the preliminary purchase price, the aggregate goodwill recognized for this business was $40 million, most of which is expected to be deductible for income tax purposes. The goodwill was assigned to the NSS reportable segment. The final purchase price allocation, which is expected to be completed by the fourth quarter of 2014, will be based on final purchase price, final appraisals and other analysis of fair values of acquired assets and liabilities. The Company does not expect that differences between the preliminary and final purchase price allocations will have a material impact on its results of operations or financial position.
	2013 Business Acquisition
	On December 19, 2013, the Company acquired Mustang Technology Group, L.P. (Mustang) business for a purchase price of $54 million, which was financed with cash on hand. The purchase price and purchase price allocation for Mustang was finalized as of June 27, 2014, with no significant changes from preliminary amounts. Mustang develops and manufactures radar-based sensors and systems used in precision-guided weapons, electronic warfare, unmanned systems and other military applications. Based on the final purchase price allocation, the aggregate goodwill recognized for this business was $41 million, most of which is expected to be deductible for income tax purposes. The goodwill was assigned to the Electronic Systems reportable segment.
	Unaudited Pro Forma Statements of Operations Data
	The following unaudited pro forma Statements of Operations data presents the combined results of the Company and its business acquisitions completed during the first half period ended June 27, 2014 and the year ended December 31, 2013, in each case assuming that the business acquisitions completed during these periods had occurred on January 1, 2013.
		Second Quarter Ended				First Half Ended
		June 27,		June 28,		June 27,		June 28,
		2014		2013		2014		2013
		(in millions, except per share data)
	Pro forma net sales	$	3,019	$	3,209	$	5,983	$	6,424
	Pro forma net income attributable to L-3	$	137	$	176	$	306	$	367
	Pro forma diluted earnings per share	$	1.53	$	1.93	$	3.42	$	4.02
	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, 2013.

Contracts_in_Process

Contracts in Process	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Contracts in Process	'
	6.  Contracts in Process
	The components of contracts in process are presented in the table below.
		June 27,			December 31,
		2014			2013
		(in millions)
	Unbilled contract receivables, gross	$	2,512		$	2,502
	Unliquidated progress payments		(906	)		(1,035	)
	Unbilled contract receivables, net		1,606			1,467
	Inventoried contract costs, gross		1,106			1,044
	Unliquidated progress payments		(79	)		(80	)
	Inventoried contract costs, net		1,027			964
	Total contracts in process	$	2,633		$	2,431
	Inventoried Contract Costs. In accordance with contract accounting standards, the Company’s U.S. Government contractor businesses account for the portion of their general and administrative (G&A), independent research and development (IRAD) and bids and proposal (B&P) costs that are allowable and reimbursable indirect contract costs under U.S. Government procurement regulations on their U.S. Government contracts (revenue arrangements) as inventoried contract costs. G&A, IRAD and B&P costs are allocated to contracts for which the U.S. Government is the end customer and are charged to costs of sales when sales on the related contracts are recognized. The Company’s U.S. Government contractor businesses record the unallowable portion of their G&A, IRAD and B&P costs to expense as incurred, and do not include them in 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.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Amounts included in inventoried contract costs at beginning of the period:	$	141		$	113		$	138		$	110
	IRAD and B&P costs		73			80			145			153
	Other G&A costs		215			232			419			437
	Total contract costs incurred		288			312			564			590
	Amounts charged to cost of sales		(278	)		(310	)		(551	)		(585	)
	Amounts included in inventoried contract costs at end of the period	$	151		$	115		$	151		$	115
	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 not included in inventoried contract costs.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Selling, general and administrative expenses	$	80		$	72		$	143		$	144
	Research and development expenses		17			25			34			45
	Total	$	97		$	97		$	177		$	189

Inventories

Inventories	6 Months Ended
	Jun. 27, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	7.  Inventories
	Inventories at Lower of Cost or Market. The table below presents the components of inventories at the lower of cost (first-in, first-out or average cost) or realizable value.
		June 27,		December 31,
		2014		2013
		(in millions)
	Raw materials, components and sub-assemblies	$	171	$	160
	Work in process		126		125
	Finished goods		76		74
	Total	$	373	$	359

Goodwill_and_Identifiable_Inta

Goodwill and Identifiable Intangible Assets	6 Months Ended
	Jun. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Identifiable Intangible Assets	'
	8.  Goodwill and Identifiable Intangible Assets
	Goodwill. In accordance with the accounting standards for business combinations, the Company records the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition (commonly referred to as the purchase price allocation). The table below presents the changes in goodwill by segment for the first half period ended June 27, 2014.
			Aerospace		Electronic			Communication		NSS		Consolidated
			Systems		Systems			Systems				Total
			(in millions)
	Balance at December 31, 2013		$	1,751	$	4,085		$	992	$	968	$	7,796
	Business acquisition(1)			—		(3	)		—		40		37
	Foreign currency translation adjustments(2)			—		4			—		1		5
	Balance at June 27, 2014		$	1,751	$	4,086		$	992	$	1,009	$	7,838
	(1)	The decrease in goodwill for the Electronic Systems segment is due to the final purchase price allocation for the Mustang business acquisition made in 2013. The increase in goodwill for the NSS segment is due to the L-3 Data Tactics business acquisition.
	(2)	The increase in goodwill presented in the Electronic Systems segment was primarily due to the weakening of the U.S. dollar against the British pound, partially offset by the strengthening of the U.S. dollar against the Euro during the first half period ended June 27, 2014. The increase in goodwill presented in the NSS segment was due to the weakening of the U.S. dollar against the British pound during the first half period ended June 27, 2014.
	The Company’s accumulated goodwill impairment losses were $58 million at June 27, 2014 and December 31, 2013, of which $43 million and $15 million were recorded in the Electronic Systems and Communication Systems segments, respectively.
	Identifiable Intangible Assets. The table below presents information for the Company’s identifiable intangible assets that are subject to amortization.
					June 27, 2014							December 31, 2013
			Weighted		Gross			Accumulated		Net		Gross		Accumulated		Net
			Average		Carrying			Amortization		Carrying		Carrying		Amortization		Carrying
			Amortization		Amount					Amount		Amount				Amount
			Period
			(in years)							(in millions)
	Customer contractual relationships			19	$	476		$	269	$	207	$	466	$	253	$	213
	Technology			11		168			112		56		168		108		60
	Other			18		27			16		11		27		15		12
	Total			17	$	671		$	397	$	274	$	661	$	376	$	285
	The table below presents amortization expense recorded by the Company for its identifiable intangible assets.
			Second Quarter Ended					First Half Ended
			(in millions)
			June 27,		June 28,			June 27,		June 28,
			2014		2013			2014		2013
	Amortization Expense		$	11	$	10		$	21	$	19
	Based on gross carrying amounts at June 27, 2014, the Company’s estimate of amortization expense for identifiable intangible assets for the years ending December 31, 2014 through 2018 is presented in the table below.
			Year Ending December 31,
			2014		2015			2016		2017		2018
			(in millions)
	Estimated amortization expense		$	43	$	41		$	34	$	33	$	26

Other_Current_Liabilities_and_

Other Current Liabilities and Other Liabilities	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Other Current Liabilities and Other Liabilities	'
	9.  Other Current Liabilities and Other Liabilities
	The table below presents the components of other current liabilities.
			June 27,			December 31,
			2014			2013
			(in millions)
	Other Current Liabilities:
	Accruals for pending and threatened litigation (see Note 18)		$	9		$	6
	Estimated costs in excess of estimated contract value to complete contracts in process in a loss position			80			78
	Accrued product warranty costs			76			75
	Accrued interest			45			52
	Deferred revenues			36			35
	Other			121			137
	Total other current liabilities		$	367		$	383
	The table below presents the components of other liabilities.
			June 27,			December 31,
			2014			2013
			(in millions)
	Other Liabilities:
	Non-current income taxes payable (see Note 11)		$	180		$	177
	Deferred compensation			47			45
	Accrued workers’ compensation			40			46
	Accrued product warranty costs			23			24
	Notes payable and capital lease obligations			10			15
	Other			95			99
	Total other liabilities		$	395		$	406
	The table below presents the changes in the Company’s accrued product warranty costs.
			First Half Ended
			June 27,			June 28,
			2014			2013
			(in millions)
	Accrued product warranty costs:(1)
	Balance at January 1		$	99		$	99
	Accruals for product warranties issued during the period			33			34
	Settlements made during the period			(33	)		(39	)
	Balance at end of period		$	99		$	94
	(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	6 Months Ended
	Jun. 27, 2014
Debt Disclosure [Abstract]	'
Debt	'
	10.  Debt
	The components of debt and a reconciliation to the carrying amount of long-term debt is presented in the table below.
			June 27,			December 31,
			2014			2013
			(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			—
	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			—
	Subtotal			3,950			2,950
	L-3 Holdings:
	3% Convertible Contingent Debt Securities due 2035 (CODES)			—			689
	Principal amount of long-term debt			3,950			3,639
	Unamortized discounts			(12	)		(9	)
	Carrying amount of long-term debt		$	3,938		$	3,630
	(1)	During the first half period ended June 27, 2014, L-3 Communications’ aggregate borrowings and repayments under the Amended and Restated Revolving Credit Facility were $1,031 million. At June 27, 2014, L-3 Communications had the availability of all of its $1 billion Amended and Restated Revolving Credit Facility, which expires on February 3, 2017.
	L-3 Communications
	Senior Notes: On May 28, 2014, L-3 Communications issued two series of Senior Notes, which are unsecured senior obligations of L-3 Communications. The terms of each series of Senior Notes are presented in the table below.
	Note		Date of Issuance			Amount			Bond		Net		Effective			Redemption
						Issued			Discount(1)		Cash		Interest			at Treasury
											Proceeds(2)		Rate			Rate(3)(4)
						(in millions)
	1.50% Senior Notes due May 28, 2017 (2017 Notes)			May 28, 2014		$	350		$	1	$	347		1.55	%		10 bps
	3.95% Senior Notes due May 28, 2024 (2024 Notes)			May 28, 2014		$	650		$	3	$	641		4.02	%		20 bps
	(1)	Bond discounts are recorded as a reduction to the principal amount of the notes and are amortized as interest expense over the term of the notes.
	(2)	The net cash proceeds of $988 million (after deduction of the bond discount, underwriting expenses and commissions and other related expenses) were used primarily to fund the CODES Retirement as discussed below. The remaining net proceeds are available for general corporate purposes.
	(3)	The 2017 Senior Notes may be redeemed at any time prior to their maturity and the 2024 Notes may be redeemed at any time prior to February 28, 2024 (three months prior to their maturity) at the option of L-3 Communications, in whole or in part, at a redemption price equal to the greater of (1) 100% of the principal amount, or (2) the present value of the remaining principal and interest payments discounted to the date of redemption, on a semi-annual basis, at the Treasury Rate (as defined in the Indentures governing the Senior Notes), plus the spread indicated in the table above. In addition, the 2024 Senior Notes may be redeemed at any time on or after February 28, 2024, at the option of L-3 Communications, in whole or in part, at a redemption price equal to 100% of the principal amount.
	(4)	Upon the occurrence of a change in control (as defined in the Indentures governing the Senior Notes), each holder of the notes will have the right to require L-3 Communications to repurchase all or any part of such holder’s notes at a price in cash equal to 101% of the aggregate principal amount plus accrued and unpaid interest, if any, but not including, the date of purchase.
	L-3 Holdings
	On May 13, 2014, the Company called for full redemption of all of its outstanding CODES effective on June 2, 2014 (the “Redemption Date”). The redemption price for the CODES was $1,000 per $1,000 principal amount of the CODES, plus accrued and unpaid interest to, but excluding, the Redemption Date. Holders of the CODES were entitled to convert all or a portion thereof (in integral multiples of $1,000) at any time prior to the close of business on the business day immediately preceding the Redemption Date (the “Redemption Conversion Period”). The conversion value of CODES of $935 million was calculated in accordance with the indenture governing the CODES based on the closing sales price of L-3 Holdings’ common stock and the conversion rate for each trading day in the 20 trading day period as follows: (1) for conversion notices received by May 16, 2014 (5 p.m.), the 20 trading day conversion period began on the third trading day following receipt of the conversion notice and (2) for conversion notices received after that time, the 20 trading day conversion period began on May 2, 2014 and ended on May 30, 2014, the trading day immediately preceding the Redemption Date. The Company settled the entire conversion value with respect to converted CODES in cash. As of the date of this report, the CODES have been retired. As a result of the conversion, the Company recorded a reduction to shareholders’ equity of $160 million related to the excess conversion value over the fair value of the debt component of the CODES, net of deferred tax liability.
	Interest income recognized was $3 million for the quarterly period ended June 27, 2014. Interest expense recognized was $2 million for the first half period ended June 27, 2014 and $5 million and $10 million for the quarterly and first half periods ended June 28, 2013. The carrying amount of the equity component (conversion feature) of the CODES was $64 million at December 31, 2013.

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 27, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	11.  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 June 27, 2014, the statutes of limitations for the Company’s U.S. Federal income tax returns for the years ended December 31, 2010 through 2012 were open. The U.S. Internal Revenue Service (IRS) commenced audits of the Company’s U.S. Federal income tax returns for 2011 and 2010. The Company cannot predict the outcome of the audits at this time.
	The effective tax rate for the first half period ended June 27, 2014 increased to 30.8% from 29.6% for the first half ended June 28, 2013. The increase was primarily due to a tax benefit in the first half period ended June 28, 2013 of $15 million related to the retroactive reinstatement in January 2013 of the U.S. Federal research and experimentation tax credit for 2012 and 2013, which did not recur in the first half period ended June 27, 2014.
	As of June 27, 2014, the Company anticipates that unrecognized tax benefits will decrease by approximately $20 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 settlement.
	Non-current income taxes payable include accrued potential interest of $13 million ($8 million after income taxes) at June 27, 2014 and $11 million ($7 million after income taxes) at December 31, 2013, and potential penalties of $7 million at June 27, 2014 and $8 million at December 31, 2013.

Amounts_Reclassified_Out_of_Ac

Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income	'
	12.  Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income
	The amounts reclassified from Accumulated Other Comprehensive (Loss) Income (AOCI) for the first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
			Foreign			Unrealized			Unrecognized			Total
			currency			gains			(losses) and			accumulated
			translation			(losses) on			prior service			other
						hedging			cost, net			comprehensive
						instruments						(loss) income
			(in millions)
	Balance at December 31, 2012		$	167		$	3		$	(720	)	$	(550	)
	Other comprehensive loss before reclassifications, net of tax			(52	)		(5	)		—			(57	)
	Amounts reclassified from other comprehensive income, net of tax			—			1			27			28
	Net current period other comprehensive (loss) income		$	(52	)	$	(4	)	$	27		$	(29	)
	Balance at June 28, 2013		$	115		$	(1	)	$	(693	)	$	(579	)
	Balance at December 31, 2013		$	142		$	1		$	(253	)	$	(110	)
	Other comprehensive income before reclassifications, net of tax			6			8			—			14
	Amounts reclassified from other comprehensive (loss) income, net of tax			—			(5	)		5			—
	Net current period other comprehensive income			6			3			5			14
	Balance at June 27, 2014		$	148		$	4		$	(248	)	$	(96	)
	Further details regarding the amounts reclassified from AOCI for the quarterly and first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
			Amount Reclassified from AOCI												Affected Line Item in the
			Second Quarter Ended						First Half Ended						Unaudited Condensed Consolidated
	Details About AOCI Components		June 27,			June 28,			June 27,			June 28,			Statements of Operations
			2014			2013			2014			2013
			(in millions)
	(Loss) gain on hedging instruments		$	(2	)	$	1		$	(7	)	$	1		Cost of sales-products
				(2	)		1			(7	)		1		Income before income taxes
				—			—			2			—		Benefit for income taxes
			$	(2	)	$	1		$	(5	)	$	1		Net income
	Amortization of defined benefit pension items:
	Net loss		$	4		$	21		$	8		$	43		(a)
				4			21			8			43		Income before income taxes
				(2	)		(7	)		(3	)		(16	)	Provision for income taxes
			$	2		$	14		$	5		$	27		Net Income
	Total reclassification for the period		$	—		$	15		$	—		$	28		Net Income
	(a)	Amounts related to pension and postretirement benefit plans were reclassified from AOCI and recorded as a component of net periodic benefit cost (see Note 19 for additional information).

Equity

Equity	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Equity	'
	13.  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. Repurchases of L-3 Holdings’ common stock under the share repurchase program are made at management’s discretion in accordance with applicable U.S. Federal securities laws in the open market or otherwise. 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 2.9 million shares of its common stock at an average price of $115.02 per share for an aggregate amount of $333 million from January 1, 2014 through June 27, 2014. All share repurchases of L-3 Holdings’ common stock have been recorded as treasury shares.
	At June 27, 2014, the remaining dollar value of authorization under the share repurchase program was $535 million. From June 28, 2014 through July 24, 2014, L-3 Holdings repurchased 505,394 shares of its common stock at an average price of $120.68 per share for an aggregate amount of $61 million.
	On May 6, 2014, L-3 Holdings’ Board of Directors declared a cash dividend of $0.60 per share, which resulted in the Company paying total cash dividends of $52 million on June 16, 2014. Also, on June 24, 2014, L-3 Holdings Board of Directors declared a quarterly cash dividend of $0.60 per share, payable on September 15, 2014, to shareholders of record at the close of business on August 18, 2014.

L3_Holdings_Earnings_Per_Commo

L-3 Holdings' Earnings Per Common Share	6 Months Ended
	Jun. 27, 2014
Earnings Per Share [Abstract]	'
L-3 Holdings' Earnings Per Common Share	'
	14.  L-3 Holdings’ Earnings Per Common Share
	A reconciliation of basic and diluted earnings per share (EPS) is presented in the table below.
			Second Quarter Ended						First Half Ended
			June 27,			June 28,			June 27,			June 28,
			2014			2013			2014			2013
			(in millions, except per share data)
	Reconciliation of net income:
	Net income		$	141		$	176		$	313		$	368
	Net income attributable to noncontrolling interests			(4	)		(1	)		(6	)		(2	)
	Net income attributable to L-3 Holdings’ common shareholders		$	137		$	175		$	307		$	366
	Earnings per share attributable to L-3 Holdings’ common shareholders:
	Basic:
	Weighted average common shares outstanding			86.1			89.9			86.1			90.1
	Basic earnings per share:
	Net income		$	1.59		$	1.95		$	3.57		$	4.06
	Diluted:
	Common and potential common shares:
	Weighted average common shares outstanding			86.1			89.9			86.1			90.1
	Assumed exercise of stock options			2.9			3.6			3.2			3.5
	Unvested restricted stock awards			1.6			1.8			1.6			1.8
	Employee stock purchase plan contributions			0.2			0.2			0.1			0.2
	Performance unit awards			0.1			0.1			0.2			0.1
	Assumed purchase of common shares for treasury			(3.3	)		(4.5	)		(3.4	)		(4.4	)
	Assumed conversion of the CODES(1)			1.7			—			1.6			—
	Common and potential common shares			89.3			91.1			89.4			91.3
	Diluted earnings per share:
	Net income		$	1.53		$	1.92		$	3.43		$	4.01
	(1)	L-3 Holdings’ CODES had no impact on diluted EPS for the quarterly and first half periods ended June 28, 2013 as the average market price of L-3 Holdings’ common stock during this period was less 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 during such period was $88.71. Although the CODES were retired during the quarterly period ended June 27, 2014, they were dilutive 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. See Note 10 regarding the retirement of the CODES.
	The computation of diluted EPS excluded shares for stock options and employee stock purchase plan contributions of 0.5 million and 0.4 million for the quarterly and first half periods ended June 27, 2014, respectively, and shares for stock options of 1.7 million for both the quarterly and first half periods ended June 28, 2013, as they were anti-dilutive.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 27, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	15.  Fair Value Measurements
	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.
			June 27, 2014						December 31, 2013
	Description		Level 1(1)		Level 2(2)		Level 3(3)		Level 1(1)		Level 2(2)		Level 3(3)
			(in millions)
	Assets
	Cash equivalents		$	88	$	—	$	—	$	299	$	—	$	—
	Derivatives (foreign currency forward contracts)			—		11		—		—		6		—
	Total assets		$	88	$	11	$	—	$	299	$	6	$	—
	Liabilities
	Derivatives (foreign currency forward contracts)		$	—	$	4	$	—	$	—	$	5	$	—
	(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	6 Months Ended
	Jun. 27, 2014
Investments, All Other Investments [Abstract]	'
Financial Instruments	'
	16.  Financial Instruments
	At June 27, 2014 and December 31, 2013, the Company’s financial instruments consisted primarily of cash and cash equivalents, billed receivables, trade accounts payable, Senior Notes, CODES 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 their 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.
			June 27, 2014				December 31, 2013
			Carrying		Estimated		Carrying		Estimated
			Amount		Fair Value		Amount		Fair Value
			(in millions)
	Senior Notes(1)		$	3,938	$	4,245	$	2,941	$	3,121
	CODES(1)			—		—		689		830
	Foreign currency forward contracts(2)			7		7		1		1
	(1)	The Company measures the fair value of its Senior Notes and CODES using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market. As of the date of this report, the CODES have been retired. See Note 10 for a description of the CODES Retirement.
	(2)	See Note 17 for additional disclosures regarding the notional amounts and fair values of foreign currency forward contracts.

Derivative_Financial_Instrumen

Derivative Financial Instruments	6 Months Ended
	Jun. 27, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	17.  Derivative Financial Instruments
	The Company’s derivative financial instruments include foreign currency forward contracts, which are entered into for risk management purposes, and an embedded derivative, at December 31, 2013, representing the contingent interest payment provision related to the CODES.
	Foreign Currency Forward Contracts. The Company’s U.S. and foreign businesses enter into contracts with customers, subcontractors or vendors that are denominated in currencies other than their functional currencies. To protect the functional currency equivalent cash flows associated with certain of these contracts, the Company enters into foreign currency forward contracts. The Company’s activities involving foreign currency forward contracts are designed to hedge the changes in the functional currency equivalent cash flows due to movements in foreign exchange rates compared to the functional currency. The foreign currencies hedged are primarily the Canadian dollar, the U.S. dollar, the Euro, and the British pound. The Company manages exposure to counterparty non-performance credit risk by entering into foreign currency forward contracts with major financial institutions that are expected to fully perform under the terms of such contracts. Foreign currency forward contracts are recorded in the Company’s condensed consolidated balance sheets at fair value and are generally designated and accounted for as cash flow hedges in accordance with the accounting standards for derivative instruments and hedging activities. Gains and losses on designated foreign currency forward contracts that are highly effective in offsetting the corresponding change in the cash flows of the hedged transactions are recorded net of income taxes in AOCI and then recognized in income when the underlying hedged transaction affects income. Gains and losses on foreign currency forward contracts that do not meet hedge accounting criteria are recognized in income immediately. Notional amounts are used to measure the volume of foreign currency forward contracts and do not represent exposure to foreign currency losses. The table below presents the notional amounts of the Company’s outstanding foreign currency forward contracts by currency at June 27, 2014.
	Currency		Notional Amounts
			(in millions)
	Canadian dollar		$	198
	U.S. dollar			107
	Euro			71
	British pound			11
	Other			2
	Total		$	389
	At June 27, 2014, the Company’s foreign currency forward contracts had maturities through 2018.
	Embedded Derivative. The embedded derivative related to the issuance of the CODES is recorded at fair value, which was zero at December 31, 2013. The table below presents the location of the Company’s derivative instruments recorded at fair value on the condensed consolidated balance sheets.
			June 27, 2014								December 31, 2013
			Other		Other		Other		Other		Other		Other		Other		Other
			Current		Assets		Current		Liabilities		Current		Assets		Current		Liabilities
			Assets				Liabilities				Assets				Liabilities
			(in millions)
	Derivatives designated as hedging instruments:
	Foreign currency forward contracts(1)		$	7	$	4	$	2	$	2	$	5	$	1	$	3	$	2
	Derivatives not designated as hedging instruments:
	Foreign currency forward contracts(1)			—		—		—		—		—		—		—		—
	Embedded derivative related to the CODES(2)			—		—		—		—		—		—		—		—
	Total derivative instruments		$	7	$	4	$	2	$	2	$	5	$	1	$	3	$	2
	(1)	See Note 15 for a description of the fair value hierarchy related to the Company’s foreign currency forward contracts.
	(2)	See Note 10 for a description of the CODES Retirement.
	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 first half periods ended June 27, 2014 and June 28, 2013. At June 27, 2014, the estimated amount of existing losses that are expected to be reclassified into income within the next 12 months is $2 million.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 27, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	18.  Commitments and Contingencies
	Guarantees
	In connection with the spin-off of Engility Holdings, Inc. (Engility), 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.
	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 international 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. 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. International government contracts generally include comparable provisions relating to terminations for convenience or default, as well as other procurement clauses relevant to the international 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 9. Amounts recoverable from insurance contracts or third parties are recorded as assets when deemed probable. At June 27, 2014, the Company did not record any amounts for recoveries from insurance contracts or third parties in connection with the amount of liabilities recorded for pending and threatened litigation. 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, our current judgment as to the likelihood of our loss (or our current estimate as to the potential range of loss, if applicable) 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 Actions. In August 2014, Zubair Patel, Alan Nguyen and Carmen Valentino filed separate, putative class action complaints in the United States District Court for the Southern District of New York against the Company and certain of its officers. Each complaint alleges violations of federal securities laws related to misconduct and accounting errors identified by the Company at its Aerospace Systems segment, and seeks monetary damages, pre- and post-judgment interest, and fees and expenses. The Company believes the lawsuits lack merit and intends to defend against them vigorously. The Company is unable to reasonably estimate any amount or range of loss that may be incurred in connection with these matters because the proceedings are in their early stages. For a discussion of the Company’s internal review relating to the accounting matters at issue, see Note 3.
	Government Inquiries. On July 30, 2014, the Company voluntarily contacted the SEC to report information concerning its internal review related to misconduct and accounting errors identified by the Company at its Aerospace Systems segment. The Company is in contact with the SEC and the U.S. Department of Justice, has received subpoenas for documents and other materials from both agencies concerning these self-reported matters, and is fully cooperating. The Company is unable to reasonably estimate any amount or range of loss that may be incurred in connection with these inquiries because they are in their early stages.
	Kalitta Air. On January 31, 1997, a predecessor of Kalitta Air filed a lawsuit in the U.S. District Court for the Northern District of California (the trial court) asserting, among other things, negligence and negligent misrepresentation against Central Texas Airborne Systems, Inc. (CTAS), a predecessor to L-3 Integrated Systems (L-3 IS), in connection with work performed by a predecessor to CTAS to convert two Boeing 747 aircraft from passenger configuration to cargo freighters. CTAS’ insurance carrier has accepted defense of this matter and has retained counsel, subject to a reservation of rights by the insurer to dispute its obligations under the applicable insurance policies in the event a judgment is ultimately rendered against CTAS. The work at issue in the lawsuit was performed using Supplemental Type Certificates (STCs) issued in 1988 by the Federal Aviation Administration (FAA). In 1996, following completion of the work, the FAA issued an airworthiness directive with respect to the STCs that effectively grounded the aircraft. Following two jury trials (in which Kalitta Air did not prevail) and related appeals to the U.S. Court of Appeals for the Ninth Circuit (the Court of Appeals), a third jury trial for this matter began on October 31, 2011, during which Kalitta Air sought damages of approximately $235 million plus an unspecified amount of pre-judgment interest that, in other contexts, has been claimed by Kalitta Air to exceed $240 million. Following the completion of the third trial on November 30, 2011, the jury rendered a verdict in favor of CTAS, finding no negligence on the part of CTAS. The trial court entered a judgment upon the verdict on March 20, 2012. Kalitta Air filed an appeal of the judgment with the Court of Appeals on July 23, 2012, which ruled against Kalitta Air and affirmed the trial court’s judgment on November 25, 2013. On April 3, 2014, Kalitta Air filed a petition with the U.S. Supreme Court seeking review of the Court of Appeals’ decision. The U.S. Supreme Court denied Kalitta Air’s petition on June 30, 2014.
	Bashkirian Airways. On July 1, 2004, lawsuits were filed on behalf of the estates of 31 Russian children in the state courts of Washington, Arizona, California, Florida, New York and New Jersey against Honeywell, Honeywell TCAS, Thales USA, Thales France, the Company and Aviation Communications & Surveillance Systems (ACSS), which is a joint venture of L-3 and Thales. The suits relate to the crash over southern Germany of a Bashkirian Airways Tupelov TU 154M aircraft and a DHL Boeing 757 cargo aircraft. On-board the Tupelov aircraft were 9 crew members and 60 passengers, including 45 children. The Boeing aircraft carried a crew of two. Both aircraft were equipped with Honeywell/ACSS Model 2000, Change 7 Traffic Collision and Avoidance Systems (TCAS). Sensing the other aircraft, the on-board DHL TCAS instructed the DHL pilot to descend, and the Tupelov on-board TCAS instructed the Tupelov pilot to climb. However, the Swiss air traffic controller ordered the Tupelov pilot to descend. The Tupelov pilot disregarded the on-board TCAS and put the Tupelov aircraft into a descent striking the DHL aircraft in midair at approximately 35,000 feet. All crew and passengers of both planes were lost. Investigations by the National Transportation Safety Board after the crash revealed that both TCAS units were performing as designed. The suits allege negligence and strict product liability based upon the design of the units and the training provided to resolve conflicting commands and seek approximately $315 million in damages, including $150 million in punitive damages. The Company’s insurers have accepted defense of this matter and have retained counsel. The matters were consolidated in the U.S. District Court for the District of New Jersey, which then dismissed the actions on the basis of forum non conveniens. Plaintiffs representing 30 of the estates re-filed their complaint against ACSS on April 23, 2007 with the Barcelona Court’s Registry in Spain. On March 9, 2010, the court ruled in favor of the plaintiffs and entered judgment against ACSS in the amount of approximately $6.7 million, all of which represented compensatory damages. Both ACSS and the plaintiffs appealed the judgment. In May 2012, the appellate court ruled in favor of the plaintiffs and entered judgment against ACSS in the amount of $48 million. ACSS filed an appeal of the judgment with the Supreme Court of Spain on September 28, 2012. On July 1, 2013, the Supreme Court agreed to consider the appeal, and the parties are awaiting the Supreme Court’s decision. The Company believes that the ruling and the damages awarded are inconsistent with the law and evidence presented and, accordingly, that it is not probable that the Company has incurred a loss with respect to this matter. As of the date of this filing, 18 out of the 30 plaintiffs have released their claims against ACSS in consideration for payments made by the Company’s insurance carriers.
	HVC Alkmaar. On July 23, 2014, a notice of claim was received by our JovyAtlas business unit. The notice relates to losses resulting from a fire that occurred at an HVC Alkmaar bio-energy plant on July 21, 2013. The notice states that the fire resulted from the failure of an uninterruptible power supply (UPS) to provide sufficient power to act as a back-up energy supply, alleges that JovyAtlas was the manufacturer and service provider for the UPS and claims €11 million in estimated property damages and €35 million in estimated business interruption damages. The Company has tendered the notice of claim to its insurance carriers, who have commenced their own investigation.

Pension_and_Other_Postretireme

Pension and Other Postretirement Benefits	6 Months Ended
	Jun. 27, 2014
Compensation and Retirement Disclosure [Abstract]	'
Pension and Other Postretirement Benefits	'
	19.  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
		Second Quarter Ended						First Half Ended						Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,			June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013			2014			2013			2014			2013
		(in millions)
	Components of net periodic benefit cost:
	Service cost	$	27		$	33		$	54		$	65		$	1		$	1		$	2		$	2
	Interest cost		37			33			73			66			2			1			4			3
	Expected return on plan assets		(49	)		(41	)		(97	)		(83	)		(1	)		(1	)		(2	)		(2	)
	Amortization of prior service costs (credits)		—			—			1			—			—			—			(1	)		1
	Amortization of net loss (gain)		5			21			9			43			(1	)		—			(1	)		(1	)
	Curtailment loss		—			—			1			—			—			—			—			—
	Net periodic benefit cost	$	20		$	46		$	41		$	91		$	1		$	1		$	2		$	3
	Contributions. The Company contributed cash of $48 million to its pension plans and $3 million to its other postretirement benefit plans during the first half period ended June 27, 2014. The Company expects to contribute an additional $49 million to its pension plans and $7 million to its other postretirement benefit plans during the remainder of 2014.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	20.  Stock-Based Compensation
	During the first half period ended June 27, 2014, the Company granted stock-based compensation under the Amended and Restated 2008 Long Term Performance Plan (2008 LTPP) in the form of stock options, restricted stock units and performance units further discussed below.
	Stock Options. The Company granted 472,992 stock options with an exercise price of $113.67 per option, which was equal to the closing price of L-3 Holdings’ common stock on the date of grant. The options expire after 10 years from the date of grant and vest ratably over a three-year period on the annual anniversary of the date of grant. The options granted to our Chairman, President and Chief Executive Officer are also subject to performance-based vesting conditions. The weighted average grant date fair value for the options of $20.02 per option was estimated using the Black-Scholes option-pricing model. The weighted average assumptions used in the valuation model for this grant are presented in the table below.
	Expected holding period (in years)	5.5
	Expected volatility	24.4	%
	Expected dividend yield	2.7	%
	Risk-free interest rate	1.7	%
	Restricted Stock Units. The Company granted 414,067 restricted stock units with a weighted average grant date fair value of $113.67 per share. Restricted stock units automatically convert into shares of L-3 Holdings’ common stock upon vesting, and are subject to forfeiture until certain restrictions have lapsed, including a three year cliff vesting period for employees and a one year cliff vesting period for non-employee directors, in each case starting on the date of grant.
	Performance Units. The Company granted 47,467 performance units with a weighted average grant date fair value per unit of $113.67. The final payout for these units is based on the achievement of pre-determined EPS goals established by the compensation committee of the Company’s Board of Directors for the three-year period ending December 31, 2016. The payout can range from zero to 200% of the original number of units awarded, which are converted into shares of L-3 Holdings’ common stock based on the then existing closing price at the end of the performance period.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	6 Months Ended
	Jun. 27, 2014
Supplemental Cash Flow Elements [Abstract]	'
Supplemental Cash Flow Information	'
	21.  Supplemental Cash Flow Information
		First Half Ended
		June 27,		June 28,
		2014		2013
		(in millions)
	Interest paid on outstanding debt	$	86	$	86
	Income tax payments		104		137
	Income tax refunds		6		16

Segment_Information

Segment Information	6 Months Ended
	Jun. 27, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	22.  Segment Information
	The Company has four reportable segments, as described in Note 1. The Company evaluates the performance of its operating segments and 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 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.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Net Sales:
	Aerospace Systems	$	1,062		$	1,133		$	2,136		$	2,324
	Electronic Systems		1,123			1,162			2,221			2,299
	Communication Systems		538			606			1,055			1,181
	NSS		336			333			641			664
	Elimination of intercompany sales		(40	)		(45	)		(77	)		(82	)
	Consolidated total	$	3,019		$	3,189		$	5,976		$	6,386
	Operating Income:
	Aerospace Systems	$	39		$	104		$	132		$	231
	Electronic Systems		133			127			258			244
	Communication Systems		48			40			98			85
	NSS		19			19			37			40
	Consolidated total	$	239		$	290		$	525		$	600
	Depreciation and amortization:
	Aerospace Systems	$	9		$	9		$	19		$	18
	Electronic Systems		30			29			59			59
	Communication Systems		13			11			25			23
	NSS		3			3			6			6
	Consolidated total	$	55		$	52		$	109		$	106
		June 27,			December 31,
		2014			2013
		(in millions)
	Total Assets:
	Aerospace Systems	$	3,133		$	3,087
	Electronic Systems		7,115			6,928
	Communication Systems		2,097			2,130
	NSS		1,339			1,247
	Corporate		432			596
	Consolidated total	$	14,116		$	13,988

Employee_Severance_and_Termina

Employee Severance and Termination Costs	6 Months Ended
	Jun. 27, 2014
Restructuring and Related Activities [Abstract]	'
Employee Severance and Termination Costs	'
	23.  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 sequestration and other DoD budget reductions, 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 sequestration at certain affected business units, the Company recorded $20 million in employee severance and other termination costs with respect to approximately 1,300 employees during the first half period ended June 27, 2014. During the year ended December 31, 2013, the Company recorded a total of $29 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 statement of operations. The remaining balance to be paid in connection with these initiatives was $16 million at June 27, 2014 and $11 million at December 31, 2013. Employee severance and other termination costs incurred by reportable segment for the first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
		First Half Ended
		June 27,		June 28,
		2014		2013
		(in millions)
	Reportable Segment
	Aerospace Systems	$	2	$	—
	Electronic Systems		14		9
	Communication Systems		3		4
	NSS		1		1
	Consolidated	$	20	$	14

Condensed_Combining_Financial_

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries	'
	24.  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 Amended and Restated Revolving 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 Amended and Restated Revolving Credit Facility, by L-3 Holdings. The CODES, prior to the CODES Retirement, were guaranteed on a joint and several, full and unconditional basis, by L-3 Communications and the Guarantor Subsidiaries. See Note 11 to the audited consolidated financial statements for the year ended December 31, 2013, included in the Company’s Form 10-K/A. 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.
	As discussed in Note 3, the Company is revising its previously issued financial statements. As part of that revision, the Company has revised the accompanying condensed combining financial statements contained herein. The adjustments related to the internal review of the Aerospace Systems segment, excluding certain adjustments related to the Platform Systems segment, were recorded as adjustments to the Guarantor Subsidiaries financial statement amounts. Adjustments from the internal review that related to a foreign subsidiary of the Platform Systems segment, with a cumulative operating impact through June 27, 2014 of $28 million, were recorded to the Non-Guarantor Subsidiaries financial statement amounts. The adjustments for the accounting related to a sales-type lease transaction for flight simulator systems within its Electronic Systems segment have been recorded as adjustments to the L-3 Communications financial statement amounts. The adjustments for the previously identified immaterial errors were recorded as adjustments to the Guarantor Subsidiaries financial statement amounts.
		L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
		Holdings			Communications			Subsidiaries			Guarantor						L-3
		(Parent)									Subsidiaries
		(in millions)
	Condensed Combining Balance Sheets:
	At June 27, 2014:
	Current assets:
	Cash and cash equivalents	$	—		$	92		$	2		$	213		$	(8	)	$	299
	Billed receivables, net		—			333			443			283			—			1,059
	Contracts in process		—			998			1,237			398			—			2,633
	Other current assets		—			383			156			175			—			714
	Total current assets		—			1,806			1,838			1,069			(8	)		4,705
	Goodwill		—			2,307			4,327			1,204			—			7,838
	Other assets		—			803			528			242			—			1,573
	Investment in and amounts due from consolidated subsidiaries		5,904			7,215			3,808			—			(16,927	)		—
	Total assets	$	5,904		$	12,131		$	10,501		$	2,515		$	(16,935	)	$	14,116
	Current liabilities	$	—		$	894		$	979		$	629		$	(8	)	$	2,494
	Amounts due to consolidated subsidiaries		—			—			—			387			(387	)		—
	Other long-term liabilities		—			1,395			194			116			—			1,705
	Long-term debt		—			3,938			—			—			—			3,938
	Total liabilities		—			6,227			1,173			1,132			(395	)		8,137
	L-3 shareholders’ equity		5,904			5,904			9,328			1,383			(16,615	)		5,904
	Noncontrolling interests		—			—			—			—			75			75
	Total equity		5,904			5,904			9,328			1,383			(16,540	)		5,979
	Total liabilities and equity	$	5,904		$	12,131		$	10,501		$	2,515		$	(16,935	)	$	14,116
	At December 31, 2013:
	Current assets:
	Cash and cash equivalents	$	—		$	258		$	—		$	261		$	(19	)	$	500
	Billed receivables, net		—			364			401			226			—			991
	Contracts in process		—			925			1,152			354			—			2,431
	Other current assets		—			344			159			169			—			672
	Total current assets		—			1,891			1,712			1,010			(19	)		4,594
	Goodwill		—			2,307			4,326			1,163			—			7,796
	Other assets		—			838			532			228			—			1,598
	Investment in and amounts due from consolidated subsidiaries		6,670			6,940			3,744			—			(17,354	)		—
	Total assets	$	6,670		$	11,976		$	10,314		$	2,401		$	(17,373	)	$	13,988
	Current liabilities	$	—		$	914		$	1,011		$	628		$	(19	)	$	2,534
	Amounts due to consolidated subsidiaries		—			—			—			270			(270	)		—
	Other long-term liabilities		—			1,451			193			124			—			1,768
	Long-term debt		689			3,630			—			—			(689	)		3,630
	Total liabilities		689			5,995			1,204			1,022			(978	)		7,932
	L-3 shareholders’ equity		5,981			5,981			9,110			1,379			(16,470	)		5,981
	Noncontrolling interests		—			—			—			—			75			75
	Total equity		5,981			5,981			9,110			1,379			(16,395	)		6,056
	Total liabilities and equity	$	6,670		$	11,976		$	10,314		$	2,401		$	(17,373	)	$	13,988
	Condensed Combining Statements of Operations:
	For the quarter ended June 27, 2014:
	Total net sales	$	—		$	883		$	1,655		$	555		$	(74	)	$	3,019
	Total cost of sales		(14	)		(798	)		(1,552	)		(504	)		88			(2,780	)
	Operating (loss) income		(14	)		85			103			51			14			239
	Interest expense		3			(38	)		—			(1	)		(3	)		(39	)
	Interest and other income, net		—			3			—			1			—			4
	(Loss) income before income taxes		(11	)		50			103			51			11			204
	Benefit (provision) for income taxes		3			(18	)		(31	)		(14	)		(3	)		(63	)
	Equity in net income of consolidated subsidiaries		145			105			—			—			(250	)		—
	Net income		137			137			72			37			(242	)		141
	Net income attributable to noncontrolling interests		—			—			—			—			(4	)		(4	)
	Net income attributable to L-3	$	137		$	137		$	72		$	37		$	(246	)	$	137
Comprehensive income attributable to L-3	$	169		$	169		$	79		$	60		$	(308	)	$	169
For the quarter ended June 28, 2013:
Total net sales	$	—		$	992		$	1,721		$	572		$	(96	)	$	3,189
Total cost of sales		(14	)		(910	)		(1,571	)		(514	)		110			(2,899	)
Operating (loss) income		(14	)		82			150			58			14			290
Interest expense		(5	)		(44	)		—			—			5			(44	)
Interest and other income, net		—			3			1			3			—			7
(Loss) income before income taxes		(19	)		41			151			61			19			253
Benefit (provision) for income taxes		6			(16	)		(43	)		(18	)		(6	)		(77	)
Equity in net income of consolidated subsidiaries		188			150			—			—			(338	)		—
Net income		175			175			108			43			(325	)		176
Net income attributable to noncontrolling interests		—			—			—			—			(1	)		(1	)
Net income attributable to L-3	$	175		$	175		$	108		$	43		$	(326	)	$	175
Comprehensive income attributable to L-3	$	170		$	170		$	107		$	26		$	(303	)	$	170
	L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
	Holdings			Communications			Subsidiaries			Guarantor						L-3
	(Parent)									Subsidiaries
	(in millions)
Condensed Combining Statements of Operations:
For the first half ended June 27, 2014:
Total net sales	$	—		$	1,746		$	3,280		$	1,098		$	(148	)	$	5,976
Total cost of sales		(29	)		(1,567	)		(3,033	)		(999	)		177			(5,451	)
Operating (loss) income		(29	)		179			247			99			29			525
Interest expense		(2	)		(81	)		—			(1	)		2			(82	)
Interest and other income, net		—			8			—			1			—			9
(Loss) income before income taxes		(31	)		106			247			99			31			452
Benefit (provision) for income taxes		9			(33	)		(76	)		(30	)		(9	)		(139	)
Equity in net income of consolidated subsidiaries		329			234			—			—			(563	)		—
Net income		307			307			171			69			(541	)		313
Net income attributable to noncontrolling interests		—			—			—			—			(6	)		(6	)
Net income attributable to L-3	$	307		$	307		$	171		$	69		$	(547	)	$	307
Comprehensive income attributable to L-3	$	321		$	321		$	175		$	75		$	(571	)	$	321
For the first half ended June 28, 2013:
Total net sales	$	—		$	1,935		$	3,458		$	1,162		$	(169	)	$	6,386
Total cost of sales		(28	)		(1,771	)		(3,140	)		(1,044	)		197			(5,786	)
Operating (loss) income		(28	)		164			318			118			28			600
Interest expense		(10	)		(87	)		—			—			10			(87	)
Interest and other income, net		—			6			—			4			—			10
(Loss) income before income taxes		(38	)		83			318			122			38			523
Benefit (provision) for income taxes		11			(25	)		(94	)		(36	)		(11	)		(155	)
Equity in net income of consolidated subsidiaries		393			308			—			—			(701	)		—
Net income		366			366			224			86			(674	)		368
Net income attributable to noncontrolling interests		—			—			—			—			(2	)		(2	)
Net income attributable to L-3	$	366		$	366		$	224		$	86		$	(676	)	$	366
Comprehensive income attributable to L-3	$	337		$	337		$	224		$	31		$	(592	)	$	337
	L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
	Holdings			Communications			Subsidiaries			Guarantor						L-3
	(Parent)									Subsidiaries
	(in millions)
Condensed Combining Statements of Cash Flows:
For the first half ended June 27, 2014:
Operating activities:
Net cash from (used in) operating activities	$	1,375		$	107		$	152		$	3		$	(1,422	)	$	215
Investing activities:
Business acquisitions, net of cash acquired		—			(57	)		—			—			—			(57	)
Investments in L-3 Communications		(77	)		—			—			—			77			—
Other investing activities		—			(25	)		(24	)		(11	)		—			(60	)
Net cash used in investing activities		(77	)		(82	)		(24	)		(11	)		77			(117	)
Financing activities:
Proceeds from sale of senior notes		—			996			—			—			—			996
Retirement of CODES		(935	)		—			—			—			—			(935	)
Common stock repurchased		(333	)		—			—			—			—			(333	)
Dividends paid on L-3 Holdings common stock		(107	)		—			—			—			—			(107	)
Dividends paid to L-3 Holdings		—			(1,375	)		—			—			1,375			—
Investments from L-3 Holdings		—			77			—			—			(77	)		—
Other financing activities		77			111			(126	)		(40	)		58			80
Net cash used in financing activities		(1,298	)		(191	)		(126	)		(40	)		1,356			(299	)
Net (decrease) increase in cash		—			(166	)		2			(48	)		11			(201	)
Cash and cash equivalents, beginning of the period		—			258			—			261			(19	)		500
Cash and cash equivalents, end of the period	$	—		$	92		$	2		$	213		$	(8	)	$	299
For the first half ended June 28, 2013:
Net cash from operating activities	$	349		$	146		$	254		$	64		$	(417	)	$	396
Investing activities:
Business acquisitions, net of cash acquired		—			(1	)		—			—			—			(1	)
Investments in L-3 Communications		(37	)		—			—			—			37			—
Other investing activities		—			(53	)		(39	)		(11	)		—			(103	)
Net cash used in investing activities		(37	)		(54	)		(39	)		(11	)		37			(104	)
Financing activities:
Common stock repurchased		(248	)		—			—			—			—			(248	)
Dividends paid on L-3 Holdings common stock		(101	)		—			—			—			—			(101	)
Dividends paid to L-3 Holdings		—			(349	)		—			—			349			—
Investments from L-3 Holdings		—			37			—			—			(37	)		—
Other financing activities		37			94			(215	)		(50	)		179			45
Net cash used in financing activities		(312	)		(218	)		(215	)		(50	)		491			(304	)
Effect of foreign currency exchange rate changes on cash		—			—			—			(9	)		—			(9	)
Net decrease in cash		—			(126	)		—			(6	)		111			(21	)
Cash and cash equivalents, beginning of the period		—			246			—			242			(139	)		349
Cash and cash equivalents, end of the period	$	—		$	120		$	—		$	236		$	(28	)	$	328

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 27, 2014
Accounting Changes and Error Corrections [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 of L-3 Communications and (2) its guarantee of other contractual obligations of L-3 Communications and its subsidiaries. As of the date of this report, L-3 Holdings’ obligation for its 3% Convertible Contingent Debt Securities (CODES) due 2035, which were issued by on July 29, 2005, have been fully retired. See Note 10 to these unaudited financial statements. L-3 Holdings’ obligations relating to the CODES were jointly, severally, fully and unconditionally guaranteed by L-3 Communications and certain of its wholly-owned domestic subsidiaries. Accordingly, such debt was reflected as debt of L-3 Communications in its consolidated financial statements at December 31, 2013 in accordance with the accounting standards for pushdown accounting. All issuances of and conversions into L-3 Holdings’ equity securities, including grants of stock options, restricted stock, 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 24 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, 2013 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 presentation 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 nearest to 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.
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 47% of the Company’s net sales in 2013 were accounted for under contract accounting standards, of which approximately 38% were fixed-price type contracts and approximately 9% were cost-plus type contracts. For contracts 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 to 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 increased consolidated operating income by $45 million, or 9%, for the first half period ended June 27, 2014 and $54 million, or 9%, for the first half period ended June 28, 2013.
	For a more complete discussion of these estimates and assumptions, see the Form 10-K/A filed on October 10, 2014.
Adoption of New Accounting Standards	'
	Effective January 1, 2014, the Company adopted Financial Accounting Standards Board (FASB) issued amendments to an accounting standard that require an unrecognized tax benefit or portion of an unrecognized tax benefit to be presented as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except when certain conditions exist. The adoption of this standard did not impact the Company’s financial position, results of operations or cash flows.
	In June 2014, the FASB issued Accounting Standard Update (ASU) 2014-12, which provides new guidance on accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period. The update requires a reporting entity to treat a performance target that affects vesting and that could be achieved after the requisite service period as a performance condition under Accounting Standards Codification Topic (ASC) 718 Compensation — Stock Compensation, and apply existing guidance as it relates to awards with performance conditions that affect vesting to account for such awards. The update is effective for the Company for the interim and annual periods beginning after December 15, 2015. The Company is currently evaluating the impact of the adoption of this standard, if any, on our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. One of the core principles of the new standard is that a company should recognize revenue based on the satisfaction of performance obligations, which depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard will be effective for the Company for interim and annual reporting periods beginning January 1, 2017. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company is currently evaluating the expected impact of the adoption of this standard on our consolidated financial statements and the transition alternatives available.
	In April 2014, the FASB issued an accounting standards update that provides new guidance on the accounting and reporting of discontinued operations. Under the new guidance, only disposals representing a strategic shift in operations should be presented as discontinued operations. Those strategic shifts should have a major effect on the organization’s operations and financial results. Additionally, the new guidance requires additional disclosures about discontinued operations. The update is effective for the Company for interim and annual periods beginning January 1, 2015. The adoption of this standard is not expected to impact the Company’s financial position, results of operations or cash flows and will only affect the treatment of future discontinued operations.

Revisions_to_Previously_Issued1

Revisions to Previously Issued Financial Statements (Tables)	6 Months Ended
	Jun. 27, 2014
Accounting Changes and Error Corrections [Abstract]	'
Schedule of Nature of Adjustments, Applicable Segment, Amount of Increase (or Decrease) to Sales and Operating Income, Period Recorded and Correct Period	'
	With respect to each of these immaterial out of period amounts included in the Company’s previously issued financial statements, the table below presents the: (1) nature of the adjustments, (2) applicable segment and (3) amount of increase (or decrease) to sales and operating income for the quarters ended December 31, September 27, June 28, and March 29, 2013.
					December 31,								September 27,								June 28,								March 29,
					2013								2013								2013								2013
	Nature of Adjustment		Applicable		Sales				Operating				Sales				Operating				Sales				Operating				Sales				Operating
			Segment						Income								Income								Income								Income
					($ in millions)
	Higher development and material costs for networked communications systems		Communication Systems		$	—			$	—			$	—			$	—			$	—			$	—			$	10			$	10
	Sub-contractor subscription deposit		Aerospace Systems			5				—				7				1				7				1				7				1
	Costs accruals for goods/services received		Aerospace Systems			—				—				—				—				—				—				5				1
	Unrecorded liabilities		Aerospace Systems			—				—				—				—				—				—				(2	)			—
	Accrued vacation		Aerospace Systems			—				6				—				(2	)			—				(2	)			—				(2	)
	Overstated revenue		Aerospace Systems			4				—				(4	)			—				—				—				—				—
	Warranty reserve		Electronic Systems			—				—				—				—				—				—				—				—
	Total				$	9			$	6			$	3			$	(1	)		$	7			$	(1	)		$	20			$	10
Schedule of Impact on Sales and Pre-tax Income	'
	The table below presents the impact of the matters discussed above on sales and pre-tax income in total, for the six month period ended June 27, 2014, years ended December 31, 2013, 2012, and 2011, and for the years ended prior to December 31, 2011.
			Total								Six Months								2013								2012								2011						Prior to 2011
											2014
			Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales			Pre-tax			Sales			Pre-tax
							Income								Income								Income								Income							Income						Income
			(in millions)
	Army C-12 Contract		$	(32	)		$	(69	)		$	(3	)		$	(15	)		$	(25	)		$	(35	)		$	(3	)		$	(16	)		$	(1	)	$	(3	)	$	—		$	—
	Other Logistics Support Contracts			(5	)			(48	)			—				(20	)			(2	)			(11	)			(2	)			(11	)			—			(2	)		(1	)		(4	)
	Logistics Solutions			(37	)			(117	)			(3	)			(35	)			(27	)			(46	)			(5	)			(27	)			(1	)		(5	)		(1	)		(4	)
	Platform Systems			(21	)			(52	)			(12	)			(40	)			(12	)			(14	)			3				2				—			—			—			—
	Total Internal Review of Aerospace Systems Segment			(58	)			(169	)			(15	)			(75	)			(39	)			(60	)			(2	)			(25	)			(1	)		(5	)		(1	)		(4	)
	Sales-Type Lease Transaction			(15	)			29				(8	)			1				(7	)			5				—				3				—			3			—			17
	Out of Period Amounts			—				—				—				—				39				14				(36	)			(18	)			(3	)		4			—			—
	Total Revisions		$	(73	)		$	(140	)		$	(23	)		$	(74	)		$	(7	)		$	(41	)		$	(38	)		$	(40	)		$	(4	)	$	2		$	(1	)	$	13
	The table below presents the impact of the matters discussed above on sales and pre-tax income for the quarters ended June 27 and March 28, 2014, December 31, September 27, June 28, 2013 and March 29, 2013.
			June 27,								March 28,								December 31,								September 27,								June 28,						March 29,
			2014								2014								2013								2013								2013						2013
			Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales				Pre-tax				Sales			Pre-tax			Sales			Pre-tax
							Income								Income								Income								Income							Income						Income
			(in millions)
	Army C-12 Contract		$	(1	)		$	(11	)		$	(2	)		$	(4	)		$	(24	)		$	(20	)		$	3			$	(2	)		$	(3	)	$	(7	)	$	(1	)	$	(6	)
	Other Logistics Support Contracts			—				(15	)			—				(5	)			(1	)			(2	)			(1	)			(5	)			—			(2	)		—			(2	)
	Logistics Solutions			(1	)			(26	)			(2	)			(9	)			(25	)			(22	)			2				(7	)			(3	)		(9	)		(1	)		(8	)
	Platform Systems			(6	)			(29	)			(6	)			(11	)			(2	)			(2	)			1				—				(6	)		(6	)		(5	)		(6	)
	Total Internal Review of Aerospace			(7	)			(55	)			(8	)			(20	)			(27	)			(24	)			3				(7	)			(9	)		(15	)		(6	)		(14	)
	Systems Segment
	Sales-Type Lease Transaction			(3	)			1				(5	)			—				(3	)			1				(1	)			2				(1	)		1			(2	)		1
	Out of Period Amounts			—				—				—				—				9				6				3				(1	)			7			(1	)		20			10
	Total Revisions		$	(10	)		$	(54	)		$	(13	)		$	(20	)		$	(21	)		$	(17	)		$	5			$	(6	)		$	(3	)	$	(15	)	$	12		$	(3	)
Schedule of As Previously Reported, Adjustments and As Currently Reported Financial Statements	'
	The tables below present the Company’s: (1) As Previously Reported, (2) Adjustments, and (3) As Currently Reported Condensed Consolidated Statements of Operations for the quarterly and first half periods ended June 28, 2013 and the Operating Activities for the Statement of Cash Flows for the first half period ended June 28, 2013. The Adjustments correct for: (1) the results of the Aerospace Systems internal review, (2) the accounting related to a sales-type lease transaction within the Company’s Electronic Systems segment and (3) immaterial out of period amounts previously recorded in the Company’s financial statements but not recorded in the appropriate period to reflect them in the appropriate period.
							Adjustments for:
			As				Aerospace				Sales- Type				Out of Period				As
			Previously				Systems				Lease				Amounts				Revised
			Reported				Segment				Transaction
							Internal
							Review
			(in millions, except per share data)
	Unaudited Condensed Consolidated Statement of Operations, for the second quarter ended June 28, 2013:
	Net sales:
	Products		$	1,810			$	(6	)		$	(1	)		$	—			$	1,803
	Services			1,382				(3	)			—				7				1,386
	Total net sales			3,192				(9	)			(1	)			7				3,189
	Cost of sales:
	Products			(1,623	)			(1	)			2				(1	)			(1,623	)
	Services			(1,262	)			(6	)			—				(8	)			(1,276	)
	Total cost of sales			(2,885	)			(7	)			2				(9	)			(2,899	)
	Operating income			307				(16	)			1				(2	)(1)			290
	Interest expense			(44	)			—				—				—				(44	)
	Interest and other income, net			5				—				1				1				7
	Income before income taxes			268				(16	)			2				(1	)			253
	Provision for income taxes			(82	)			6				(1	)			—				(77	)
	Net income		$	186			$	(10	)		$	1			$	(1	)		$	176
	Net income attributable to noncontrolling interests			(1	)			—				—				—				(1	)
	Net income attributable to L-3		$	185			$	(10	)		$	1			$	(1	)		$	175
	Earnings per share attributable to L-3 Holdings’ common shareholders:
	Basic		$	2.06			$	(0.11	)		$	0.01			$	(0.01	)		$	1.95
	Diluted		$	2.03			$	(0.11	)		$	0.01			$	(0.01	)		$	1.92
	Cash dividends paid per common share		$	0.55			$	—			$	—			$	—			$	0.55
	L-3 Holdings’ weighted average common shares outstanding:
	Basic			89.9				—				—				—				89.9
	Diluted			91.1				—				—				—				91.1
	-1	Includes rounding of $1 million.
							Adjustments for:
			As				Aerospace				Sales- Type				Out of Period				As
			Previously				Systems				Lease				Amounts				Revised
			Reported				Segment				Transaction
							Internal
							Review
			(in millions, except per share data)
	Unaudited Condensed Consolidated Statement of Operations, for the first half ended June 28, 2013:
	Net sales:
	Products		$	3,623			$	(10	)		$	(3	)		$	14			$	3,624
	Services			2,754				(4	)			—				12				2,762
	Total net sales			6,377				(14	)			(3	)			26				6,386
	Cost of sales:
	Products			(3,243	)			(2	)			4				(4	)			(3,245	)
	Services			(2,514	)			(13	)			—				(14	)			(2,541	)
	Total cost of sales			(5,757	)			(15	)			4				(18	)			(5,786	)
	Operating income			620				(29	)			1				8				600
	Interest expense			(87	)			—				—				—				(87	)
	Interest and other income, net			8				—				2				—				10
	Income before income taxes			541				(29	)			3				8				523
	Provision for income taxes			(161	)			10				(1	)			(3	)			(155	)
	Net income		$	380			$	(19	)		$	2			$	5			$	368
	Net income attributable to noncontrolling interests			(2	)			—				—				—				(2	)
	Net income attributable to L-3		$	378			$	(19	)		$	2			$	5			$	366
	Earnings per share attributable to L-3 Holdings’ common shareholders:
	Basic		$	4.2			$	(0.21	)		$	0.02			$	0.05			$	4.06
	Diluted		$	4.14			$	(0.20	)		$	0.02			$	0.05			$	4.01
	Cash dividends paid per common share		$	1.1			$	—			$	—			$	—			$	1.1
	L-3 Holdings’ weighted average common shares outstanding:
	Basic			90.1				—				—				—				90.1
Diluted			91.3				—				—				—				91.3
		As				Net				As
		Previously				Adjustments				Revised
		Reported
		(in millions)
Unaudited Consolidated Statement of Cash Flows for first half ended June 28, 2013:
Operating activities:
Net income		$	380			$	(12	)		$	368
Depreciation of property, plant and equipment			81				—				81
Amortization of intangibles and other assets			25				—				25
Deferred income tax provision			13				(5	)			8
Stock-based employee compensation expense			28				—				28
Contributions to employee savings plans in L-3 Holdings’ common stock			61				—				61
Amortization of pension and postretirement benefit plans net loss and prior service cost			43				—				43
Amortization of bond discounts and deferred debt issue costs (included in interest expense)			3				—				3
Other non-cash items			—				—				—
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:
Billed receivables			(76	)			—				(76	)
Contracts in process			(10	)			(41	)			(51	)
Inventories			(17	)			—				(17	)
Other assets			(44	)			(2	)			(46	)
Accounts payable, trade			50				(12	)			38
Accrued employment costs			20				7				27
Accrued expenses			(64	)			(6	)			(70	)
Advance payments and billings in excess of costs incurred			(89	)			48				(41	)
Income taxes			27				(2	)			25
Excess income tax benefits related to share-based payment arrangements			(2	)			—				(2	)
Other current liabilities			(3	)			3				—
Pension and postretirement benefits			3				—				3
All other operating activities			(33	)			22				(11	)
Net cash (used in) from operating activities		$	396			$	—			$	396

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended
	Jun. 27, 2014
Business Combinations [Abstract]	'
Unaudited Pro Forma Statements of Operations Data	'
	The following unaudited pro forma Statements of Operations data presents the combined results of the Company and its business acquisitions completed during the first half period ended June 27, 2014 and the year ended December 31, 2013, in each case assuming that the business acquisitions completed during these periods had occurred on January 1, 2013.
		Second Quarter Ended				First Half Ended
		June 27,		June 28,		June 27,		June 28,
		2014		2013		2014		2013
		(in millions, except per share data)
	Pro forma net sales	$	3,019	$	3,209	$	5,983	$	6,424
	Pro forma net income attributable to L-3	$	137	$	176	$	306	$	367
	Pro forma diluted earnings per share	$	1.53	$	1.93	$	3.42	$	4.02

Contracts_in_Process_Tables

Contracts in Process (Tables)	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Components of Contracts in Process	'
	The components of contracts in process are presented in the table below.
		June 27,			December 31,
		2014			2013
		(in millions)
	Unbilled contract receivables, gross	$	2,512		$	2,502
	Unliquidated progress payments		(906	)		(1,035	)
	Unbilled contract receivables, net		1,606			1,467
	Inventoried contract costs, gross		1,106			1,044
	Unliquidated progress payments		(79	)		(80	)
	Inventoried contract costs, net		1,027			964
	Total contracts in process	$	2,633		$	2,431
General and Administrative, Independent Research and Development and Bids 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.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Amounts included in inventoried contract costs at beginning of the period:	$	141		$	113		$	138		$	110
	IRAD and B&P costs		73			80			145			153
	Other G&A costs		215			232			419			437
	Total contract costs incurred		288			312			564			590
	Amounts charged to cost of sales		(278	)		(310	)		(551	)		(585	)
	Amounts included in inventoried contract costs at end of the period	$	151		$	115		$	151		$	115
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 not included in inventoried contract costs.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Selling, general and administrative expenses	$	80		$	72		$	143		$	144
	Research and development expenses		17			25			34			45
	Total	$	97		$	97		$	177		$	189

Inventories_Tables

Inventories (Tables)	6 Months Ended
	Jun. 27, 2014
Inventory Disclosure [Abstract]	'
Inventories at Lower of Cost or Market	'
	Inventories at Lower of Cost or Market. The table below presents the components of inventories at the lower of cost (first-in, first-out or average cost) or realizable value.
		June 27,		December 31,
		2014		2013
		(in millions)
	Raw materials, components and sub-assemblies	$	171	$	160
	Work in process		126		125
	Finished goods		76		74
	Total	$	373	$	359

Goodwill_and_Identifiable_Inta1

Goodwill and Identifiable Intangible Assets (Tables)	6 Months Ended
	Jun. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in Goodwill by Segment	'
	The table below presents the changes in goodwill by segment for the first half period ended June 27, 2014.
			Aerospace		Electronic			Communication		NSS		Consolidated
			Systems		Systems			Systems				Total
			(in millions)
	Balance at December 31, 2013		$	1,751	$	4,085		$	992	$	968	$	7,796
	Business acquisition(1)			—		(3	)		—		40		37
	Foreign currency translation adjustments(2)			—		4			—		1		5
	Balance at June 27, 2014		$	1,751	$	4,086		$	992	$	1,009	$	7,838
	(1)	The decrease in goodwill for the Electronic Systems segment is due to the final purchase price allocation for the Mustang business acquisition made in 2013. The increase in goodwill for the NSS segment is due to the L-3 Data Tactics business acquisition.
	(2)	The increase in goodwill presented in the Electronic Systems segment was primarily due to the weakening of the U.S. dollar against the British pound, partially offset by the strengthening of the U.S. dollar against the Euro during the first half period ended June 27, 2014. The increase in goodwill presented in the NSS segment was due to the weakening of the U.S. dollar against the British pound during the first half period ended June 27, 2014.
Identifiable Intangible Assets	'
	The table below presents information for the Company’s identifiable intangible assets that are subject to amortization.
					June 27, 2014							December 31, 2013
			Weighted		Gross			Accumulated		Net		Gross		Accumulated		Net
			Average		Carrying			Amortization		Carrying		Carrying		Amortization		Carrying
			Amortization		Amount					Amount		Amount				Amount
			Period
			(in years)							(in millions)
	Customer contractual relationships			19	$	476		$	269	$	207	$	466	$	253	$	213
	Technology			11		168			112		56		168		108		60
	Other			18		27			16		11		27		15		12
	Total			17	$	671		$	397	$	274	$	661	$	376	$	285
Amortization Expense	'
	The table below presents amortization expense recorded by the Company for its identifiable intangible assets.
			Second Quarter Ended					First Half Ended
			(in millions)
			June 27,		June 28,			June 27,		June 28,
			2014		2013			2014		2013
	Amortization Expense		$	11	$	10		$	21	$	19
Estimated Amortization Expense	'
	Based on gross carrying amounts at June 27, 2014, the Company’s estimate of amortization expense for identifiable intangible assets for the years ending December 31, 2014 through 2018 is presented in the table below.
			Year Ending December 31,
			2014		2015			2016		2017		2018
			(in millions)
	Estimated amortization expense		$	43	$	41		$	34	$	33	$	26

Other_Current_Liabilities_and_1

Other Current Liabilities and Other Liabilities (Tables)	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Other Current Liabilities	'
	The table below presents the components of other current liabilities.
			June 27,			December 31,
			2014			2013
			(in millions)
	Other Current Liabilities:
	Accruals for pending and threatened litigation (see Note 18)		$	9		$	6
	Estimated costs in excess of estimated contract value to complete contracts in process in a loss position			80			78
	Accrued product warranty costs			76			75
	Accrued interest			45			52
	Deferred revenues			36			35
	Other			121			137
	Total other current liabilities		$	367		$	383
Other Liabilities	'
	The table below presents the components of other liabilities.
			June 27,			December 31,
			2014			2013
			(in millions)
	Other Liabilities:
	Non-current income taxes payable (see Note 11)		$	180		$	177
	Deferred compensation			47			45
	Accrued workers’ compensation			40			46
	Accrued product warranty costs			23			24
	Notes payable and capital lease obligations			10			15
	Other			95			99
	Total other liabilities		$	395		$	406
Changes in Company's Accrued Product Warranty Costs	'
	The table below presents the changes in the Company’s accrued product warranty costs.
			First Half Ended
			June 27,			June 28,
			2014			2013
			(in millions)
	Accrued product warranty costs:(1)
	Balance at January 1		$	99		$	99
	Accruals for product warranties issued during the period			33			34
	Settlements made during the period			(33	)		(39	)
	Balance at end of period		$	99		$	94
	(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)	6 Months Ended
	Jun. 27, 2014
Debt Disclosure [Abstract]	'
Components of Debt and Reconciliation to Carrying Amount of Long-Term Debt	'
	The components of debt and a reconciliation to the carrying amount of long-term debt is presented in the table below.
			June 27,			December 31,
			2014			2013
			(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			—
	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			—
	Subtotal			3,950			2,950
	L-3 Holdings:
	3% Convertible Contingent Debt Securities due 2035 (CODES)			—			689
	Principal amount of long-term debt			3,950			3,639
	Unamortized discounts			(12	)		(9	)
	Carrying amount of long-term debt		$	3,938		$	3,630
	(1)	During the first half period ended June 27, 2014, L-3 Communications’ aggregate borrowings and repayments under the Amended and Restated Revolving Credit Facility were $1,031 million. At June 27, 2014, L-3 Communications had the availability of all of its $1 billion Amended and Restated Revolving Credit Facility, which expires on February 3, 2017.
Information Regarding Outstanding Series of Senior Subordinated Note	'
	The terms of each series of Senior Notes are presented in the table below.
	Note		Date of Issuance			Amount			Bond		Net		Effective			Redemption
						Issued			Discount(1)		Cash		Interest			at Treasury
											Proceeds(2)		Rate			Rate(3)(4)
						(in millions)
	1.50% Senior Notes due May 28, 2017 (2017 Notes)			May 28, 2014		$	350		$	1	$	347		1.55	%		10 bps
	3.95% Senior Notes due May 28, 2024 (2024 Notes)			May 28, 2014		$	650		$	3	$	641		4.02	%		20 bps
	(1)	Bond discounts are recorded as a reduction to the principal amount of the notes and are amortized as interest expense over the term of the notes.
	(2)	The net cash proceeds of $988 million (after deduction of the bond discount, underwriting expenses and commissions and other related expenses) were used primarily to fund the CODES Retirement as discussed below. The remaining net proceeds are available for general corporate purposes.
	(3)	The 2017 Senior Notes may be redeemed at any time prior to their maturity and the 2024 Notes may be redeemed at any time prior to February 28, 2024 (three months prior to their maturity) at the option of L-3 Communications, in whole or in part, at a redemption price equal to the greater of (1) 100% of the principal amount, or (2) the present value of the remaining principal and interest payments discounted to the date of redemption, on a semi-annual basis, at the Treasury Rate (as defined in the Indentures governing the Senior Notes), plus the spread indicated in the table above. In addition, the 2024 Senior Notes may be redeemed at any time on or after February 28, 2024, at the option of L-3 Communications, in whole or in part, at a redemption price equal to 100% of the principal amount.
	(4)	Upon the occurrence of a change in control (as defined in the Indentures governing the Senior Notes), each holder of the notes will have the right to require L-3 Communications to repurchase all or any part of such holder’s notes at a price in cash equal to 101% of the aggregate principal amount plus accrued and unpaid interest, if any, but not including, the date of purchase.

Amounts_Reclassified_Out_of_Ac1

Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income (Tables)	6 Months Ended
	Jun. 27, 2014
Text Block [Abstract]	'
Summary of Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income	'
	The amounts reclassified from Accumulated Other Comprehensive (Loss) Income (AOCI) for the first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
			Foreign			Unrealized			Unrecognized			Total
			currency			gains			(losses) and			accumulated
			translation			(losses) on			prior service			other
						hedging			cost, net			comprehensive
						instruments						(loss) income
			(in millions)
	Balance at December 31, 2012		$	167		$	3		$	(720	)	$	(550	)
	Other comprehensive loss before reclassifications, net of tax			(52	)		(5	)		—			(57	)
	Amounts reclassified from other comprehensive income, net of tax			—			1			27			28
	Net current period other comprehensive (loss) income		$	(52	)	$	(4	)	$	27		$	(29	)
	Balance at June 28, 2013		$	115		$	(1	)	$	(693	)	$	(579	)
	Balance at December 31, 2013		$	142		$	1		$	(253	)	$	(110	)
	Other comprehensive income before reclassifications, net of tax			6			8			—			14
	Amounts reclassified from other comprehensive (loss) income, net of tax			—			(5	)		5			—
	Net current period other comprehensive income			6			3			5			14
	Balance at June 27, 2014		$	148		$	4		$	(248	)	$	(96	)
	Further details regarding the amounts reclassified from AOCI for the quarterly and first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
			Amount Reclassified from AOCI												Affected Line Item in the
			Second Quarter Ended						First Half Ended						Unaudited Condensed Consolidated
	Details About AOCI Components		June 27,			June 28,			June 27,			June 28,			Statements of Operations
			2014			2013			2014			2013
			(in millions)
	(Loss) gain on hedging instruments		$	(2	)	$	1		$	(7	)	$	1		Cost of sales-products
				(2	)		1			(7	)		1		Income before income taxes
				—			—			2			—		Benefit for income taxes
			$	(2	)	$	1		$	(5	)	$	1		Net income
	Amortization of defined benefit pension items:
	Net loss		$	4		$	21		$	8		$	43		(a)
				4			21			8			43		Income before income taxes
				(2	)		(7	)		(3	)		(16	)	Provision for income taxes
			$	2		$	14		$	5		$	27		Net Income
	Total reclassification for the period		$	—		$	15		$	—		$	28		Net Income
	(a)	Amounts related to pension and postretirement benefit plans were reclassified from AOCI and recorded as a component of net periodic benefit cost (see Note 19 for additional information).

L3_Holdings_Earnings_Per_Commo1

L-3 Holdings' Earnings Per Common Share (Tables)	6 Months Ended
	Jun. 27, 2014
Earnings Per Share [Abstract]	'
Reconciliation of Basic and Diluted Earnings Per Share	'
	A reconciliation of basic and diluted earnings per share (EPS) is presented in the table below.
			Second Quarter Ended						First Half Ended
			June 27,			June 28,			June 27,			June 28,
			2014			2013			2014			2013
			(in millions, except per share data)
	Reconciliation of net income:
	Net income		$	141		$	176		$	313		$	368
	Net income attributable to noncontrolling interests			(4	)		(1	)		(6	)		(2	)
	Net income attributable to L-3 Holdings’ common shareholders		$	137		$	175		$	307		$	366
	Earnings per share attributable to L-3 Holdings’ common shareholders:
	Basic:
	Weighted average common shares outstanding			86.1			89.9			86.1			90.1
	Basic earnings per share:
	Net income		$	1.59		$	1.95		$	3.57		$	4.06
	Diluted:
	Common and potential common shares:
	Weighted average common shares outstanding			86.1			89.9			86.1			90.1
	Assumed exercise of stock options			2.9			3.6			3.2			3.5
	Unvested restricted stock awards			1.6			1.8			1.6			1.8
	Employee stock purchase plan contributions			0.2			0.2			0.1			0.2
	Performance unit awards			0.1			0.1			0.2			0.1
	Assumed purchase of common shares for treasury			(3.3	)		(4.5	)		(3.4	)		(4.4	)
	Assumed conversion of the CODES(1)			1.7			—			1.6			—
	Common and potential common shares			89.3			91.1			89.4			91.3
	Diluted earnings per share:
	Net income		$	1.53		$	1.92		$	3.43		$	4.01
	(1)	L-3 Holdings’ CODES had no impact on diluted EPS for the quarterly and first half periods ended June 28, 2013 as the average market price of L-3 Holdings’ common stock during this period was less 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 during such period was $88.71. Although the CODES were retired during the quarterly period ended June 27, 2014, they were dilutive 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. See Note 10 regarding the retirement of the CODES.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 27, 2014
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.
			June 27, 2014						December 31, 2013
	Description		Level 1(1)		Level 2(2)		Level 3(3)		Level 1(1)		Level 2(2)		Level 3(3)
			(in millions)
	Assets
	Cash equivalents		$	88	$	—	$	—	$	299	$	—	$	—
	Derivatives (foreign currency forward contracts)			—		11		—		—		6		—
	Total assets		$	88	$	11	$	—	$	299	$	6	$	—
	Liabilities
	Derivatives (foreign currency forward contracts)		$	—	$	4	$	—	$	—	$	5	$	—
	(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)	6 Months Ended
	Jun. 27, 2014
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.
			June 27, 2014				December 31, 2013
			Carrying		Estimated		Carrying		Estimated
			Amount		Fair Value		Amount		Fair Value
			(in millions)
	Senior Notes(1)		$	3,938	$	4,245	$	2,941	$	3,121
	CODES(1)			—		—		689		830
	Foreign currency forward contracts(2)			7		7		1		1
	(1)	The Company measures the fair value of its Senior Notes and CODES using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market. As of the date of this report, the CODES have been retired. See Note 10 for a description of the CODES Retirement.
	(2)	See Note 17 for additional disclosures regarding the notional amounts and fair values of foreign currency forward contracts.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 27, 2014
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 June 27, 2014.
	Currency		Notional Amounts
			(in millions)
	Canadian dollar		$	198
	U.S. dollar			107
	Euro			71
	British pound			11
	Other			2
	Total		$	389
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.
			June 27, 2014								December 31, 2013
			Other		Other		Other		Other		Other		Other		Other		Other
			Current		Assets		Current		Liabilities		Current		Assets		Current		Liabilities
			Assets				Liabilities				Assets				Liabilities
			(in millions)
	Derivatives designated as hedging instruments:
	Foreign currency forward contracts(1)		$	7	$	4	$	2	$	2	$	5	$	1	$	3	$	2
	Derivatives not designated as hedging instruments:
	Foreign currency forward contracts(1)			—		—		—		—		—		—		—		—
	Embedded derivative related to the CODES(2)			—		—		—		—		—		—		—		—
	Total derivative instruments		$	7	$	4	$	2	$	2	$	5	$	1	$	3	$	2
	(1)	See Note 15 for a description of the fair value hierarchy related to the Company’s foreign currency forward contracts.
	(2)	See Note 10 for a description of the CODES Retirement.

Pension_and_Other_Postretireme1

Pension and Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 27, 2014
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
		Second Quarter Ended						First Half Ended						Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,			June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013			2014			2013			2014			2013
		(in millions)
	Components of net periodic benefit cost:
	Service cost	$	27		$	33		$	54		$	65		$	1		$	1		$	2		$	2
	Interest cost		37			33			73			66			2			1			4			3
	Expected return on plan assets		(49	)		(41	)		(97	)		(83	)		(1	)		(1	)		(2	)		(2	)
	Amortization of prior service costs (credits)		—			—			1			—			—			—			(1	)		1
	Amortization of net loss (gain)		5			21			9			43			(1	)		—			(1	)		(1	)
	Curtailment loss		—			—			1			—			—			—			—			—
	Net periodic benefit cost	$	20		$	46		$	41		$	91		$	1		$	1		$	2		$	3

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Weighted Average Assumptions used 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)	5.5
	Expected volatility	24.4	%
	Expected dividend yield	2.7	%
	Risk-free interest rate	1.7	%

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 27, 2014
Supplemental Cash Flow Elements [Abstract]	'
Supplemental Cash Flow Information	'
		First Half Ended
		June 27,		June 28,
		2014		2013
		(in millions)
	Interest paid on outstanding debt	$	86	$	86
	Income tax payments		104		137
	Income tax refunds		6		16

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended
	Jun. 27, 2014
Segment Reporting [Abstract]	'
Summary of Segment Information	'
	The tables below present net sales, operating income, depreciation and amortization and total assets by reportable segment.
		Second Quarter Ended						First Half Ended
		June 27,			June 28,			June 27,			June 28,
		2014			2013			2014			2013
		(in millions)
	Net Sales:
	Aerospace Systems	$	1,062		$	1,133		$	2,136		$	2,324
	Electronic Systems		1,123			1,162			2,221			2,299
	Communication Systems		538			606			1,055			1,181
	NSS		336			333			641			664
	Elimination of intercompany sales		(40	)		(45	)		(77	)		(82	)
	Consolidated total	$	3,019		$	3,189		$	5,976		$	6,386
	Operating Income:
	Aerospace Systems	$	39		$	104		$	132		$	231
	Electronic Systems		133			127			258			244
	Communication Systems		48			40			98			85
	NSS		19			19			37			40
	Consolidated total	$	239		$	290		$	525		$	600
	Depreciation and amortization:
	Aerospace Systems	$	9		$	9		$	19		$	18
	Electronic Systems		30			29			59			59
	Communication Systems		13			11			25			23
	NSS		3			3			6			6
	Consolidated total	$	55		$	52		$	109		$	106
		June 27,			December 31,
		2014			2013
		(in millions)
	Total Assets:
	Aerospace Systems	$	3,133		$	3,087
	Electronic Systems		7,115			6,928
	Communication Systems		2,097			2,130
	NSS		1,339			1,247
	Corporate		432			596
	Consolidated total	$	14,116		$	13,988

Employee_Severance_and_Termina1

Employee Severance and Termination Costs (Tables)	6 Months Ended
	Jun. 27, 2014
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 first half periods ended June 27, 2014 and June 28, 2013 are presented in the table below.
		First Half Ended
		June 27,		June 28,
		2014		2013
		(in millions)
	Reportable Segment
	Aerospace Systems	$	2	$	—
	Electronic Systems		14		9
	Communication Systems		3		4
	NSS		1		1
	Consolidated	$	20	$	14

Condensed_Combining_Financial_1

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries (Tables)	6 Months Ended
	Jun. 27, 2014
Text Block [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.
	As discussed in Note 3, the Company is revising its previously issued financial statements. As part of that revision, the Company has revised the accompanying condensed combining financial statements contained herein. The adjustments related to the internal review of the Aerospace Systems segment, excluding certain adjustments related to the Platform Systems segment, were recorded as adjustments to the Guarantor Subsidiaries financial statement amounts. Adjustments from the internal review that related to a foreign subsidiary of the Platform Systems segment, with a cumulative operating impact through June 27, 2014 of $28 million, were recorded to the Non-Guarantor Subsidiaries financial statement amounts. The adjustments for the accounting related to a sales-type lease transaction for flight simulator systems within its Electronic Systems segment have been recorded as adjustments to the L-3 Communications financial statement amounts. The adjustments for the previously identified immaterial errors were recorded as adjustments to the Guarantor Subsidiaries financial statement amounts.
		L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
		Holdings			Communications			Subsidiaries			Guarantor						L-3
		(Parent)									Subsidiaries
		(in millions)
	Condensed Combining Balance Sheets:
	At June 27, 2014:
	Current assets:
	Cash and cash equivalents	$	—		$	92		$	2		$	213		$	(8	)	$	299
	Billed receivables, net		—			333			443			283			—			1,059
	Contracts in process		—			998			1,237			398			—			2,633
	Other current assets		—			383			156			175			—			714
	Total current assets		—			1,806			1,838			1,069			(8	)		4,705
	Goodwill		—			2,307			4,327			1,204			—			7,838
	Other assets		—			803			528			242			—			1,573
	Investment in and amounts due from consolidated subsidiaries		5,904			7,215			3,808			—			(16,927	)		—
	Total assets	$	5,904		$	12,131		$	10,501		$	2,515		$	(16,935	)	$	14,116
	Current liabilities	$	—		$	894		$	979		$	629		$	(8	)	$	2,494
	Amounts due to consolidated subsidiaries		—			—			—			387			(387	)		—
	Other long-term liabilities		—			1,395			194			116			—			1,705
	Long-term debt		—			3,938			—			—			—			3,938
	Total liabilities		—			6,227			1,173			1,132			(395	)		8,137
	L-3 shareholders’ equity		5,904			5,904			9,328			1,383			(16,615	)		5,904
	Noncontrolling interests		—			—			—			—			75			75
	Total equity		5,904			5,904			9,328			1,383			(16,540	)		5,979
	Total liabilities and equity	$	5,904		$	12,131		$	10,501		$	2,515		$	(16,935	)	$	14,116
	At December 31, 2013:
	Current assets:
	Cash and cash equivalents	$	—		$	258		$	—		$	261		$	(19	)	$	500
	Billed receivables, net		—			364			401			226			—			991
	Contracts in process		—			925			1,152			354			—			2,431
	Other current assets		—			344			159			169			—			672
	Total current assets		—			1,891			1,712			1,010			(19	)		4,594
	Goodwill		—			2,307			4,326			1,163			—			7,796
	Other assets		—			838			532			228			—			1,598
	Investment in and amounts due from consolidated subsidiaries		6,670			6,940			3,744			—			(17,354	)		—
	Total assets	$	6,670		$	11,976		$	10,314		$	2,401		$	(17,373	)	$	13,988
	Current liabilities	$	—		$	914		$	1,011		$	628		$	(19	)	$	2,534
	Amounts due to consolidated subsidiaries		—			—			—			270			(270	)		—
	Other long-term liabilities		—			1,451			193			124			—			1,768
	Long-term debt		689			3,630			—			—			(689	)		3,630
	Total liabilities		689			5,995			1,204			1,022			(978	)		7,932
	L-3 shareholders’ equity		5,981			5,981			9,110			1,379			(16,470	)		5,981
	Noncontrolling interests		—			—			—			—			75			75
	Total equity		5,981			5,981			9,110			1,379			(16,395	)		6,056
	Total liabilities and equity	$	6,670		$	11,976		$	10,314		$	2,401		$	(17,373	)	$	13,988
Condensed Combining Statements of Operations	'
	Condensed Combining Statements of Operations:
	For the quarter ended June 27, 2014:
	Total net sales	$	—		$	883		$	1,655		$	555		$	(74	)	$	3,019
	Total cost of sales		(14	)		(798	)		(1,552	)		(504	)		88			(2,780	)
	Operating (loss) income		(14	)		85			103			51			14			239
	Interest expense		3			(38	)		—			(1	)		(3	)		(39	)
	Interest and other income, net		—			3			—			1			—			4
	(Loss) income before income taxes		(11	)		50			103			51			11			204
	Benefit (provision) for income taxes		3			(18	)		(31	)		(14	)		(3	)		(63	)
	Equity in net income of consolidated subsidiaries		145			105			—			—			(250	)		—
	Net income		137			137			72			37			(242	)		141
	Net income attributable to noncontrolling interests		—			—			—			—			(4	)		(4	)
	Net income attributable to L-3	$	137		$	137		$	72		$	37		$	(246	)	$	137
	Comprehensive income attributable to L-3	$	169		$	169		$	79		$	60		$	(308	)	$	169
	For the quarter ended June 28, 2013:
	Total net sales	$	—		$	992		$	1,721		$	572		$	(96	)	$	3,189
	Total cost of sales		(14	)		(910	)		(1,571	)		(514	)		110			(2,899	)
	Operating (loss) income		(14	)		82			150			58			14			290
	Interest expense		(5	)		(44	)		—			—			5			(44	)
	Interest and other income, net		—			3			1			3			—			7
	(Loss) income before income taxes		(19	)		41			151			61			19			253
	Benefit (provision) for income taxes		6			(16	)		(43	)		(18	)		(6	)		(77	)
	Equity in net income of consolidated subsidiaries		188			150			—			—			(338	)		—
	Net income		175			175			108			43			(325	)		176
	Net income attributable to noncontrolling interests		—			—			—			—			(1	)		(1	)
	Net income attributable to L-3	$	175		$	175		$	108		$	43		$	(326	)	$	175
	Comprehensive income attributable to L-3	$	170		$	170		$	107		$	26		$	(303	)	$	170
		L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
		Holdings			Communications			Subsidiaries			Guarantor						L-3
		(Parent)									Subsidiaries
		(in millions)
	Condensed Combining Statements of Operations:
	For the first half ended June 27, 2014:
	Total net sales	$	—		$	1,746		$	3,280		$	1,098		$	(148	)	$	5,976
	Total cost of sales		(29	)		(1,567	)		(3,033	)		(999	)		177			(5,451	)
	Operating (loss) income		(29	)		179			247			99			29			525
	Interest expense		(2	)		(81	)		—			(1	)		2			(82	)
	Interest and other income, net		—			8			—			1			—			9
	(Loss) income before income taxes		(31	)		106			247			99			31			452
	Benefit (provision) for income taxes		9			(33	)		(76	)		(30	)		(9	)		(139	)
	Equity in net income of consolidated subsidiaries		329			234			—			—			(563	)		—
	Net income		307			307			171			69			(541	)		313
	Net income attributable to noncontrolling interests		—			—			—			—			(6	)		(6	)
	Net income attributable to L-3	$	307		$	307		$	171		$	69		$	(547	)	$	307
	Comprehensive income attributable to L-3	$	321		$	321		$	175		$	75		$	(571	)	$	321
	For the first half ended June 28, 2013:
	Total net sales	$	—		$	1,935		$	3,458		$	1,162		$	(169	)	$	6,386
	Total cost of sales		(28	)		(1,771	)		(3,140	)		(1,044	)		197			(5,786	)
	Operating (loss) income		(28	)		164			318			118			28			600
	Interest expense		(10	)		(87	)		—			—			10			(87	)
	Interest and other income, net		—			6			—			4			—			10
	(Loss) income before income taxes		(38	)		83			318			122			38			523
	Benefit (provision) for income taxes		11			(25	)		(94	)		(36	)		(11	)		(155	)
	Equity in net income of consolidated subsidiaries		393			308			—			—			(701	)		—
	Net income		366			366			224			86			(674	)		368
	Net income attributable to noncontrolling interests		—			—			—			—			(2	)		(2	)
	Net income attributable to L-3	$	366		$	366		$	224		$	86		$	(676	)	$	366
	Comprehensive income attributable to L-3	$	337		$	337		$	224		$	31		$	(592	)	$	337
Condensed Combining Statements of Cash Flows	'
		L-3			L-3			Guarantor			Non-			Eliminations			Consolidated
		Holdings			Communications			Subsidiaries			Guarantor						L-3
		(Parent)									Subsidiaries
		(in millions)
	Condensed Combining Statements of Cash Flows:
	For the first half ended June 27, 2014:
	Operating activities:
	Net cash from (used in) operating activities	$	1,375		$	107		$	152		$	3		$	(1,422	)	$	215
	Investing activities:
	Business acquisitions, net of cash acquired		—			(57	)		—			—			—			(57	)
	Investments in L-3 Communications		(77	)		—			—			—			77			—
	Other investing activities		—			(25	)		(24	)		(11	)		—			(60	)
	Net cash used in investing activities		(77	)		(82	)		(24	)		(11	)		77			(117	)
	Financing activities:
	Proceeds from sale of senior notes		—			996			—			—			—			996
	Retirement of CODES		(935	)		—			—			—			—			(935	)
	Common stock repurchased		(333	)		—			—			—			—			(333	)
	Dividends paid on L-3 Holdings common stock		(107	)		—			—			—			—			(107	)
	Dividends paid to L-3 Holdings		—			(1,375	)		—			—			1,375			—
	Investments from L-3 Holdings		—			77			—			—			(77	)		—
	Other financing activities		77			111			(126	)		(40	)		58			80
	Net cash used in financing activities		(1,298	)		(191	)		(126	)		(40	)		1,356			(299	)
	Net (decrease) increase in cash		—			(166	)		2			(48	)		11			(201	)
	Cash and cash equivalents, beginning of the period		—			258			—			261			(19	)		500
	Cash and cash equivalents, end of the period	$	—		$	92		$	2		$	213		$	(8	)	$	299
	For the first half ended June 28, 2013:
	Net cash from operating activities	$	349		$	146		$	254		$	64		$	(417	)	$	396
	Investing activities:
	Business acquisitions, net of cash acquired		—			(1	)		—			—			—			(1	)
	Investments in L-3 Communications		(37	)		—			—			—			37			—
	Other investing activities		—			(53	)		(39	)		(11	)		—			(103	)
	Net cash used in investing activities		(37	)		(54	)		(39	)		(11	)		37			(104	)
	Financing activities:
	Common stock repurchased		(248	)		—			—			—			—			(248	)
	Dividends paid on L-3 Holdings common stock		(101	)		—			—			—			—			(101	)
	Dividends paid to L-3 Holdings		—			(349	)		—			—			349			—
	Investments from L-3 Holdings		—			37			—			—			(37	)		—
	Other financing activities		37			94			(215	)		(50	)		179			45
	Net cash used in financing activities		(312	)		(218	)		(215	)		(50	)		491			(304	)
	Effect of foreign currency exchange rate changes on cash		—			—			—			(9	)		—			(9	)
	Net decrease in cash		—			(126	)		—			(6	)		111			(21	)
	Cash and cash equivalents, beginning of the period		—			246			—			242			(139	)		349
	Cash and cash equivalents, end of the period	$	—		$	120		$	—		$	236		$	(28	)	$	328

Description_of_Business_Additi

Description of Business - Additional Information (Detail)	6 Months Ended
	Jun. 27, 2014
	Segment
Disclosure Description Of Business Additional Information [Abstract]	'
Number of segments	4

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Summary Of Significant Accounting Policies [Line Items]	'	'
Percentage of sales accounted for under contract accounting standards	47.00%	'
Percentage of fixed-price type contracts	38.00%	'
Percentage of cost-plus type contracts	9.00%	'
Period of performance for contracts accounted for under the percentage-of-completion method of accounting, minimum	'1 year	'
Increase in operating income due to changes in contract estimates	$45	$54
Percentage of increase in operating income due to changes in contract estimates	9.00%	9.00%
CODES Due 2035 [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Interest rate on debt instruments	3.00%	'
Debt instruments, maturity year	'2035	'

Revisions_to_Previously_Issued2

Revisions to Previously Issued Financial Statements - Additional Information (Detail) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

6 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Logistics Solutions [Member]

Platform Systems [Member]

Army C-12 Contract [Member]

Other Logistics Support Contracts [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Change in Accounting Estimate [Line Items]

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Aggregate pre-tax charge as a result of internal review

$204

$253

$452

$523

($54)

($20)

($17)

($6)

($15)

($3)

'

($41)

($40)

$2

($140)

($55)

($20)

($24)

($7)

($15)

($14)

'

($60)

($25)

($5)

($169)

($26)

($9)

($22)

($7)

($9)

($8)

'

($46)

($27)

($5)

($117)

($29)

($11)

($2)

'

($6)

($6)

'

($14)

$2

'

($52)

($11)

($4)

($20)

($2)

($7)

($6)

'

($35)

($16)

($3)

($69)

($15)

($5)

($2)

($5)

($2)

($2)

'

($11)

($11)

($2)

($48)

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$1

'

$1

$2

$1

$1

'

$5

$3

$3

$29

$13

($4)

($4)

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($4)

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$17

Cumulative aggregate adjustments, net

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-117

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-52

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Cumulative aggregate adjustments losses

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37

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69

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48

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Adjustment description

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'The Platform Systems sector adjustments are primarily due to: (1) losses of $37 million on two aircraft modification contracts and two contracts for rotary wing sub-assemblies and parts, and (2) write-offs of deferred costs of $15 million to design and test aerostructures for a new commercial aircraft.

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Write-offs of deferred costs

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15

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Lease period

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'The period of performance under this contract began in 2004 and ends in 2023.

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Increase in interest income

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5

3

3

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12

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Decrease in sales

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-74

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-75

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-35

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-40

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-15

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-20

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-8

-7

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1

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Decrease in cost of sales

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($7)

($7)

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($5)

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Revisions_to_Previously_Issued3

Revisions to Previously Issued Financial Statements - Schedule of Nature of Adjustments, Applicable Segment, Amount of Increase (or Decrease) to Sales and Operating Income, Period Recorded and Correct Period (Detail) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Communication Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Higher Development and Material Costs for Networked Communications Systems [Member]

Higher Development and Material Costs for Networked Communications Systems [Member]

Higher Development and Material Costs for Networked Communications Systems [Member]

Higher Development and Material Costs for Networked Communications Systems [Member]

Sub-Contractor Subscription Deposit [Member]

Sub-Contractor Subscription Deposit [Member]

Sub-Contractor Subscription Deposit [Member]

Sub-Contractor Subscription Deposit [Member]

Costs Accruals for Goods/Services Received [Member]

Costs Accruals for Goods/Services Received [Member]

Costs Accruals for Goods/Services Received [Member]

Costs Accruals for Goods/Services Received [Member]

Unrecorded Liabilities [Member]

Unrecorded Liabilities [Member]

Unrecorded Liabilities [Member]

Unrecorded Liabilities [Member]

Accrued Vacation [Member]

Accrued Vacation [Member]

Accrued Vacation [Member]

Accrued Vacation [Member]

Overstated Revenue [Member]

Overstated Revenue [Member]

Overstated Revenue [Member]

Overstated Revenue [Member]

Warranty Reserve [Member]

Warranty Reserve [Member]

Warranty Reserve [Member]

Warranty Reserve [Member]

Quantifying Misstatement in Current Year Financial Statements [Line Items]

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Sales

$3,019

$3,189

$5,976

$6,386

($10)

($13)

($21)

$5

($3)

$12

($23)

($7)

($38)

($4)

($73)

$9

$3

$7

$20

'

'

'

$10

'

'

$9

$3

$7

$20

'

$39

($36)

($3)

'

$5

$7

$7

$7

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$5

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'

'

($2)

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$4

($4)

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Operating income

$239

$290

$525

$600

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$6

($1)

($1)

$10

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$10

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$1

$1

$1

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$1

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$6

($2)

($2)

($2)

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Revisions_to_Previously_Issued4

Revisions to Previously Issued Financial Statements - Schedule of Impact on Sales and Pre-tax Income (Detail) (USD $)

3 Months Ended

6 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Prior to 2011 [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Army C-12 Contract [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Other Logistics Support Contracts [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Logistics Solutions [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Platform Systems [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Sales-Type Lease Transaction [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Out of Period Amounts [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Army C-12 Contract [Member]

Other Logistics Support Contracts [Member]

Logistics Solutions [Member]

Platform Systems [Member]

Total Internal Review of Aerospace Systems Segment [Member]

Sales-Type Lease Transaction [Member]

Out of Period Amounts [Member]

Quantifying Misstatement in Current Year Financial Statements [Line Items]

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Sales

$3,019

$3,189

$5,976

$6,386

'

'

$9

$3

$7

$20

($10)

($13)

($21)

$5

($3)

$12

($23)

($7)

($38)

($4)

($73)

($1)

($2)

($24)

$3

($3)

($1)

($3)

($25)

($3)

($1)

($32)

'

'

($1)

($1)

'

'

'

($2)

($2)

'

($5)

($1)

($2)

($25)

$2

($3)

($1)

($3)

($27)

($5)

($1)

($37)

($6)

($6)

($2)

$1

($6)

($5)

($12)

($12)

$3

'

($21)

($7)

($8)

($27)

$3

($9)

($6)

($15)

($39)

($2)

($1)

($58)

($3)

($5)

($3)

($1)

($1)

($2)

($8)

($7)

'

'

($15)

'

'

$9

$3

$7

$20

'

$39

($36)

($3)

'

($1)

'

($1)

($1)

'

($1)

'

'

Pre-tax Income

204

253

452

523

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'

'

-54

-20

-17

-6

-15

-3

'

-41

-40

2

-140

-11

-4

-20

-2

-7

-6

'

-35

-16

-3

-69

-15

-5

-2

-5

-2

-2

'

-11

-11

-2

-48

-26

-9

-22

-7

-9

-8

'

-46

-27

-5

-117

-29

-11

-2

'

-6

-6

'

-14

2

'

-52

-55

-20

-24

-7

-15

-14

'

-60

-25

-5

-169

1

'

1

2

1

1

'

5

3

3

29

'

'

6

-1

-1

10

'

14

-18

4

'

13

'

-4

-4

'

-4

17

'

Pre-tax Income

'

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($8)

($7)

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($74)

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($15)

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($20)

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($35)

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($40)

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($75)

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$1

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Revisions_to_Previously_Issued5

Revisions to Previously Issued Financial Statements - Schedule of Condensed Consolidated Statement of Operations (Detail) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended					6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013	Dec. 31, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013	Jun. 28, 2013
					Out of Period Amounts [Member]	Out of Period Amounts [Member]	Out of Period Amounts [Member]	Out of Period Amounts [Member]	As Previously Reported [Member]	As Previously Reported [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]	Restatement Adjustments [Member]
												Aerospace Systems Segment Internal Review [Member ]	Aerospace Systems Segment Internal Review [Member ]	Sales-Type Lease Transaction [Member]	Sales-Type Lease Transaction [Member]	Out of Period Amounts [Member]	Out of Period Amounts [Member]
Net sales:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Products	$1,698	$1,803	$3,347	$3,624	'	'	'	'	$1,810	$3,623	'	($6)	($10)	($1)	($3)	'	$14
Services	1,321	1,386	2,629	2,762	'	'	'	'	1,382	2,754	'	-3	-4	'	'	7	12
Total net sales	3,019	3,189	5,976	6,386	9	3	7	20	3,192	6,377	'	-9	-14	-1	-3	7	26
Cost of sales:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Products	-1,552	-1,623	-3,018	-3,245	'	'	'	'	-1,623	-3,243	'	-1	-2	2	4	-1	-4
Services	-1,228	-1,276	-2,433	-2,541	'	'	'	'	-1,262	-2,514	'	-6	-13	'	'	-8	-14
Total cost of sales	-2,780	-2,899	-5,451	-5,786	'	'	'	'	-2,885	-5,757	'	-7	-15	2	4	-9	-18
Operating income	239	290	525	600	6	-1	-1	10	307	620	'	-16	-29	1	1	-2	8
Interest expense	-39	-44	-82	-87	'	'	'	'	-44	-87	'	'	'	'	'	'	'
Interest and other income, net	4	7	9	10	'	'	'	'	5	8	'	'	'	1	2	1	'
Income before income taxes	204	253	452	523	'	'	'	'	268	541	'	-16	-29	2	3	-1	8
Provision for income taxes	-63	-77	-139	-155	'	'	'	'	-82	-161	'	6	10	-1	-1	'	-3
Net income	141	176	313	368	'	'	'	'	186	380	-12	-10	-19	1	2	-1	5
Net income attributable to noncontrolling interests	-4	-1	-6	-2	'	'	'	'	-1	-2	'	'	'	'	'	'	'
Net income attributable to L-3	$137	$175	$307	$366	'	'	'	'	$185	$378	'	($10)	($19)	$1	$2	($1)	$5
Earnings per share attributable to L-3 Holdings' common shareholders:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Basic	$1.59	$1.95	$3.57	$4.06	'	'	'	'	$2.06	$4.20	'	($0.11)	($0.21)	$0.01	$0.02	($0.01)	$0.05
Diluted	$1.53	$1.92	$3.43	$4.01	'	'	'	'	$2.03	$4.14	'	($0.11)	($0.20)	$0.01	$0.02	($0.01)	$0.05
Cash dividends paid per common share	$0.60	$0.55	$1.20	$1.10	'	'	'	'	$0.55	$1.10	'	'	'	'	'	'	'
L-3 Holdings' weighted average common shares outstanding:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Basic	86.1	89.9	86.1	90.1	'	'	'	'	89.9	90.1	'	'	'	'	'	'	'
Diluted	89.3	91.1	89.4	91.3	'	'	'	'	91.1	91.3	'	'	'	'	'	'	'

Revisions_to_Previously_Issued6

Revisions to Previously Issued Financial Statements - Schedule of Condensed Consolidated Statement of Cash Flows (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Operating activities:	'	'
Net income	$313	$368
Depreciation of property, plant and equipment	84	81
Amortization of intangibles and other assets	25	25
Deferred income tax provision	43	8
Stock-based employee compensation expense	29	28
Contributions to employee savings plans in L-3 Holdings' common stock	74	61
Amortization of pension and postretirement benefit plans net loss and prior service cost	8	43
Amortization of bond discounts and deferred debt issue costs (included in interest expense)	3	3
Other non-cash items	4	'
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:	'	'
Billed receivables	-61	-76
Contracts in process	-195	-51
Inventories	-14	-17
Other assets	8	-46
Accounts payable, trade	8	38
Accrued employment costs	-3	27
Accrued expenses	-71	-70
Advance payments and billings in excess of costs incurred	49	-41
Income taxes	-1	25
Excess income tax benefits related to share-based payment arrangements	-16	-2
Other current liabilities	-17	'
Pension and postretirement benefits	-16	3
All other operating activities	-31	-11
Net cash (used in) from operating activities	215	396
As Previously Reported [Member]	'	'
Operating activities:	'	'
Net income	'	380
Depreciation of property, plant and equipment	'	81
Amortization of intangibles and other assets	'	25
Deferred income tax provision	'	13
Stock-based employee compensation expense	'	28
Contributions to employee savings plans in L-3 Holdings' common stock	'	61
Amortization of pension and postretirement benefit plans net loss and prior service cost	'	43
Amortization of bond discounts and deferred debt issue costs (included in interest expense)	'	3
Other non-cash items	'	'
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:	'	'
Billed receivables	'	-76
Contracts in process	'	-10
Inventories	'	-17
Other assets	'	-44
Accounts payable, trade	'	50
Accrued employment costs	'	20
Accrued expenses	'	-64
Advance payments and billings in excess of costs incurred	'	-89
Income taxes	'	27
Excess income tax benefits related to share-based payment arrangements	'	-2
Other current liabilities	'	-3
Pension and postretirement benefits	'	3
All other operating activities	'	-33
Net cash (used in) from operating activities	'	396
Restatement Adjustments [Member]	'	'
Operating activities:	'	'
Net income	'	-12
Depreciation of property, plant and equipment	'	'
Amortization of intangibles and other assets	'	'
Deferred income tax provision	'	-5
Stock-based employee compensation expense	'	'
Contributions to employee savings plans in L-3 Holdings' common stock	'	'
Amortization of pension and postretirement benefit plans net loss and prior service cost	'	'
Amortization of bond discounts and deferred debt issue costs (included in interest expense)	'	'
Other non-cash items	'	'
Changes in operating assets and liabilities, excluding amounts from acquisitions and divestitures:	'	'
Billed receivables	'	'
Contracts in process	'	-41
Inventories	'	'
Other assets	'	-2
Accounts payable, trade	'	-12
Accrued employment costs	'	7
Accrued expenses	'	-6
Advance payments and billings in excess of costs incurred	'	48
Income taxes	'	-2
Excess income tax benefits related to share-based payment arrangements	'	'
Other current liabilities	'	3
Pension and postretirement benefits	'	'
All other operating activities	'	22
Net cash (used in) from operating activities	'	'

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013	Mar. 04, 2014	Jun. 27, 2014	Dec. 19, 2013
In Millions, unless otherwise specified			2014 Business Acquisition [Member]	2013 Business Acquisition [Member]	2013 Business Acquisition [Member]
Business Acquisition [Line Items]	'	'	'	'	'
Purchase price of acquisition	'	'	$57	'	$54
Amount of goodwill recognized	7,838	7,796	40	41	'
Goodwill deductible for income tax purposes	'	'	$40	$41	'

Acquisitions_Unaudited_Pro_For

Acquisitions - Unaudited Pro Forma Statements of Operations Data (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Business Combinations [Abstract]	'	'	'	'
Pro forma net sales	$3,019	$3,209	$5,983	$6,424
Pro forma net income attributable to L-3	$137	$176	$306	$367
Pro forma diluted earnings per share	$1.53	$1.93	$3.42	$4.02

Contracts_in_Process_Component

Contracts in Process - Components of Contracts in Process (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Components of contracts in process	'	'
Unbilled contract receivables, gross	$2,512	$2,502
Unliquidated progress payments	-906	-1,035
Unbilled contract receivables, net	1,606	1,467
Inventoried contract costs, gross	1,106	1,044
Unliquidated progress payments	-79	-80
Inventoried contract costs, net	1,027	964
Total contracts in process	$2,633	$2,431

Contracts_in_Process_General_a

Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Inventory Disclosure [Abstract]	'	'	'	'
Amounts included in inventoried contract costs at beginning of the period:	$141	$113	$138	$110
IRAD and B&P costs	73	80	145	153
Other G&A costs	215	232	419	437
Total contract costs incurred	288	312	564	590
Amounts charged to cost of sales	-278	-310	-551	-585
Amounts included in inventoried contract costs at end of the period	$151	$115	$151	$115

Contracts_in_Process_Selling_G

Contracts in Process - Selling, General and Administrative Expenses and Research and Development Expenses (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Inventory Disclosure [Abstract]	'	'	'	'
Selling, general and administrative expenses	$80	$72	$143	$144
Research and development expenses	17	25	34	45
Total	$97	$97	$177	$189

Inventories_Inventories_at_Low

Inventories - Inventories at Lower of Cost or Market (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials, components and sub-assemblies	$171	$160
Work in process	126	125
Finished goods	76	74
Total	$373	$359

Goodwill_and_Identifiable_Inta2

Goodwill and Identifiable Intangible Assets - Changes in Goodwill by Segment (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014
Goodwill [Line Items]	'
Balance, Beginning	$7,796
Business acquisition	37
Foreign currency translation adjustments	5
Balance, Ending	7,838
Aerospace Systems [Member]	'
Goodwill [Line Items]	'
Balance, Beginning	1,751
Business acquisition	'
Foreign currency translation adjustments	'
Balance, Ending	1,751
Electronic Systems [Member]	'
Goodwill [Line Items]	'
Balance, Beginning	4,085
Business acquisition	-3
Foreign currency translation adjustments	4
Balance, Ending	4,086
Communication Systems [Member]	'
Goodwill [Line Items]	'
Balance, Beginning	992
Business acquisition	'
Foreign currency translation adjustments	'
Balance, Ending	992
NSS [Member]	'
Goodwill [Line Items]	'
Balance, Beginning	968
Business acquisition	40
Foreign currency translation adjustments	1
Balance, Ending	$1,009

Goodwill_and_Identifiable_Inta3

Goodwill and Identifiable Intangible Assets - Additional Information (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Goodwill [Line Items]	'	'
Accumulated goodwill impairment losses	$58	$58
Electronic Systems [Member]	'	'
Goodwill [Line Items]	'	'
Accumulated goodwill impairment losses	43	43
Communication Systems [Member]	'	'
Goodwill [Line Items]	'	'
Accumulated goodwill impairment losses	$15	$15

Goodwill_and_Identifiable_Inta4

Goodwill and Identifiable Intangible Assets - Identifiable Intangible Assets (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Amortization Period (in years)	'17 years	'
Gross Carrying Amount	$671	$661
Accumulated Amortization	397	376
Net Carrying Amount	274	285
Customer Contractual Relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Amortization Period (in years)	'19 years	'
Gross Carrying Amount	476	466
Accumulated Amortization	269	253
Net Carrying Amount	207	213
Technology [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Amortization Period (in years)	'11 years	'
Gross Carrying Amount	168	168
Accumulated Amortization	112	108
Net Carrying Amount	56	60
Other [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Weighted Average Amortization Period (in years)	'18 years	'
Gross Carrying Amount	27	27
Accumulated Amortization	16	15
Net Carrying Amount	$11	$12

Goodwill_and_Identifiable_Inta5

Goodwill and Identifiable Intangible Assets - Amortization Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'
Amortization Expense	$11	$10	$21	$19

Goodwill_and_Identifiable_Inta6

Goodwill and Identifiable Intangible Assets - Estimated Amortization Expense (Detail) (USD $)	Jun. 27, 2014
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
Estimated amortization expense, 2014	$43
Estimated amortization expense, 2015	41
Estimated amortization expense, 2016	34
Estimated amortization expense, 2017	33
Estimated amortization expense, 2018	$26

Other_Current_Liabilities_and_2

Other Current Liabilities and Other Liabilities - Other Current Liabilities (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Current Liabilities:	'	'
Accruals for pending and threatened litigation (see Note 18)	$9	$6
Estimated costs in excess of estimated contract value to complete contracts in process in a loss position	80	78
Accrued product warranty costs	76	75
Accrued interest	45	52
Deferred revenues	36	35
Other	121	137
Total other current liabilities	$367	$383

Other_Current_Liabilities_and_3

Other Current Liabilities and Other Liabilities - Other Liabilities (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Liabilities:	'	'
Non-current income taxes payable (see Note 11)	$180	$177
Deferred compensation	47	45
Accrued workers' compensation	40	46
Accrued product warranty costs	23	24
Notes payable and capital lease obligations	10	15
Other	95	99
Total other liabilities	$395	$406

Other_Current_Liabilities_and_4

Other Current Liabilities and Other Liabilities - Changes in Company's Accrued Product Warranty Costs (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Accrued product warranty costs:	'	'
Balance at January 1	$99	$99
Accruals for product warranties issued during the period	33	34
Settlements made during the period	-33	-39
Balance at end of period	$99	$94

Debt_Components_of_Debt_and_Re

Debt - Components of Debt and Reconciliation to Carrying Amount of Long-Term Debt (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
3% Convertible Contingent Debt Securities due 2035 (CODES)	'	$689
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	'
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	'
Subtotal	3,950	2,950
L-3 Communications Holdings, Inc. [Member]	'	'
Debt Instrument [Line Items]	'	'
3% Convertible Contingent Debt Securities due 2035 (CODES)	'	689
Principal amount of long-term debt	3,950	3,639
Unamortized discounts	-12	-9
Carrying amount of long-term debt	$3,938	$3,630

Debt_Components_of_Debt_and_Re1

Debt - Components of Debt and Reconciliation to Carrying Amount of Long-Term Debt (Parenthetical) (Detail) (USD $)

6 Months Ended

Jun. 27, 2014

Jun. 27, 2014

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

CODES Due 2035 [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Corporation [Member]

L-3 Communications Holdings, Inc. [Member]

L-3 Communications Holdings, Inc. [Member]

3.95% Senior Notes due 2016 [Member]

3.95% Senior Notes due 2016 [Member]

1.50% Senior Notes due 2017 [Member]

1.50% Senior Notes due 2017 [Member]

5.20% Senior Notes due 2019 [Member]

5.20% Senior Notes due 2019 [Member]

4.75% Senior Notes due 2020 [Member]

4.75% Senior Notes due 2020 [Member]

4.95% Senior Notes due 2021 [Member]

4.95% Senior Notes due 2021 [Member]

3.95% Senior Notes due 2024 [Member]

3.95% Senior Notes due 2024 [Member]

CODES Due 2035 [Member]

CODES Due 2035 [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on Senior Notes

'

3.00%

3.95%

3.95%

1.50%

1.50%

5.20%

5.20%

4.75%

4.75%

4.95%

4.95%

3.95%

3.95%

3.00%

3.00%

Aggregate borrowings and repayments under the Amended and Restated Revolving Credit Facility

$1,031,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Borrowings under Amended and Restated Revolving Credit Facility

$1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revolving credit facility expiration date

3-Feb-17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	0 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended			0 Months Ended
	13-May-14	Jun. 27, 2014	13-May-14	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013	Dec. 31, 2013	28-May-14
				L-3 Communications Holdings, Inc. [Member]	L-3 Communications Holdings, Inc. [Member]	L-3 Communications Holdings, Inc. [Member]	L-3 Communications Holdings, Inc. [Member]	L-3 Communications Holdings, Inc. [Member]	L-3 Communications Corporation [Member]
									Instruments
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'
Senior Notes issued	'	'	'	'	'	'	'	'	2
Principal amount of CODES	'	'	$1,000	'	'	'	'	'	'
Redemption price for CODES	'	'	1,000	'	'	'	'	'	'
Redemption date	'	2-Jun-14	'	'	'	'	'	'	'
Conversion of converted securities	935,000,000	-160,000,000	'	'	'	'	'	'	'
Number of trading days in the conversion period	'	'20 days	'	'	'	'	'	'	'
Trading day conversion description	'	'(1) for conversion notices received by May 16, 2014 (5 p.m.), the 20 trading day conversion period began on the third trading day following receipt of the conversion notice and (2) for conversion notices received	'	'	'	'	'	'	'
Excess of conversion value over fair value of the debt component	'	'	160,000,000	'	'	'	'	'	'
Interest income recognized	'	'	'	3,000,000	'	'	'	'	'
Interest expense recognized	'	'	'	'	5,000,000	2,000,000	10,000,000	'	'
Carrying amount of the equity component (conversion feature)	'	'	'	'	'	'	'	$64,000,000	'

Debt_Information_Regarding_Out

Debt - Information Regarding Outstanding Series of Senior Subordinated Note (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014
Debt Instrument [Line Items]	'
Net Cash Proceeds	$996
L-3 Communications Corporation [Member]	'
Debt Instrument [Line Items]	'
Net Cash Proceeds	988
L-3 Communications Corporation [Member] | 1.50% Senior Notes due 2017 [Member]	'
Debt Instrument [Line Items]	'
Date of Issuance	28-May-14
Amount Issued	350
Discount	1
Net Cash Proceeds	347
Effective Interest Rate	1.55%
Redemption at Treasury Rate	0.10%
Senior notes due	28-May-17
L-3 Communications Corporation [Member] | 3.95% Senior Notes due 2024 [Member]	'
Debt Instrument [Line Items]	'
Date of Issuance	28-May-14
Amount Issued	650
Discount	3
Net Cash Proceeds	$641
Effective Interest Rate	4.02%
Redemption at Treasury Rate	0.20%
Senior notes due	28-May-24
L-3 Communications Corporation [Member] | 3.95% Senior Notes due 2024 [Member] | Minimum [Member]	'
Debt Instrument [Line Items]	'
Senior notes due	28-Feb-24

Debt_Information_Regarding_Out1

Debt - Information Regarding Outstanding Series of Senior Subordinated Note (Parenthetical) (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Dec. 31, 2013
Debt Instrument [Line Items]	'	'
Net Cash Proceeds	$996	'
L-3 Communications Corporation [Member]	'	'
Debt Instrument [Line Items]	'	'
Net Cash Proceeds	988	'
Redemption price as percentage of principal amount	100.00%	'
Senior notes redemption price	101.00%	'
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%
Senior notes due	28-May-17	'
Net Cash Proceeds	347	'
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%
Senior notes due	28-May-24	'
Net Cash Proceeds	$641	'

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Dec. 31, 2013
Tax Credit Carryforward [Line Items]	'	'	'
Effective tax rate	30.80%	29.60%	'
Anticipated decrease in unrecognized tax benefits over the next 12 months	$20	'	'
Accrued potential interest included within non-current income taxes payable	13	'	11
Accrued potential interest included within non-current income taxes payable, after income taxes	8	'	7
Potential penalties	7	'	8
U.S. Federal Research and Experimentation Tax Credit [Member]	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'
Tax benefit	'	15	'

Amounts_Reclassified_Out_of_Ac2

Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income - Summary of Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Beginning Balance	'	'	($110)	($550)
Other comprehensive (loss) income before reclassifications, net of tax	'	'	14	-57
Amounts reclassified from other comprehensive (loss) income, net of tax	'	'	'	28
Net current period other comprehensive (loss) income	'	'	14	-29
Ending Balance	-96	-579	-96	-579
Cost of sales-products	1,552	1,623	3,018	3,245
Income before income taxes	204	253	452	523
(Provision) benefit for income taxes	-63	-77	-139	-155
Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net income	'	15	'	28
Foreign Currency Translation [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Beginning Balance	'	'	142	167
Other comprehensive (loss) income before reclassifications, net of tax	'	'	6	-52
Amounts reclassified from other comprehensive (loss) income, net of tax	'	'	'	'
Net current period other comprehensive (loss) income	'	'	6	-52
Ending Balance	148	115	148	115
Unrealized Gains (Losses) on Hedging Instruments [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Beginning Balance	'	'	1	3
Other comprehensive (loss) income before reclassifications, net of tax	'	'	8	-5
Amounts reclassified from other comprehensive (loss) income, net of tax	'	'	-5	1
Net current period other comprehensive (loss) income	'	'	3	-4
Ending Balance	4	-1	4	-1
Unrealized Gains (Losses) on Hedging Instruments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Cost of sales-products	-2	1	-7	1
Income before income taxes	-2	1	-7	1
(Provision) benefit for income taxes	'	'	2	'
Net income	-2	1	-5	1
Unrecognized (Losses) Gains and Prior Service Cost, Net [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Beginning Balance	'	'	-253	-720
Other comprehensive (loss) income before reclassifications, net of tax	'	'	'	'
Amounts reclassified from other comprehensive (loss) income, net of tax	'	'	5	27
Net current period other comprehensive (loss) income	'	'	5	27
Ending Balance	-248	-693	-248	-693
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net loss	4	21	8	43
Income before income taxes	4	21	8	43
(Provision) benefit for income taxes	-2	-7	-3	-16
Net income	$2	$14	$5	$27

Equity_Additional_Information_

Equity - Additional Information (Detail) (USD $)	0 Months Ended				6 Months Ended		1 Months Ended	6 Months Ended		1 Months Ended
	Jun. 24, 2014	Jun. 16, 2014	Mar. 06, 2014	Feb. 05, 2013	Jun. 27, 2014	Jun. 28, 2013	Jul. 24, 2014	Jun. 27, 2014	Jun. 28, 2013	Jul. 24, 2014
							February 5, 2013 Share Repurchase Program [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]
							Subsequent Event [Member]			February 5, 2013 Share Repurchase Program [Member]
										Subsequent Event [Member]
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'	'
Amount of shares authorized to be repurchased	'	'	'	$1,500,000,000	'	'	'	'	'	'
Average price per share of repurchased shares	'	'	'	'	$115.02	'	$120.68	'	'	'
Number of common shares repurchased	'	'	'	'	'	'	'	2,900,000	3,100,000	505,394
Aggregate amount of repurchased shares	'	'	'	'	333,000,000	248,000,000	61,000,000	'	'	'
Remaining value under share repurchase program	'	'	'	'	535,000,000	'	'	'	'	'
Cash dividend, declared per share	$0.60	'	$0.60	'	'	'	'	'	'	'
Total cash dividends	'	$52,000,000	'	'	$104,000,000	$99,000,000	'	'	'	'
Dividend declared date	'	'	'	'	24-Jun-14	'	'	'	'	'
Dividend payable date	'	'	'	'	15-Sep-14	'	'	'	'	'

L3_Holdings_Earnings_Per_Commo2

L-3 Holdings' Earnings Per Common Share - Reconciliation of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Reconciliation of net income:	'	'	'	'
Net income	$141	$176	$313	$368
Net income attributable to noncontrolling interests	-4	-1	-6	-2
Net income attributable to L-3 Holdings' common shareholders	$137	$175	$307	$366
Basic:	'	'	'	'
Weighted average common shares outstanding	86.1	89.9	86.1	90.1
Basic earnings per share:	'	'	'	'
Net income	$1.59	$1.95	$3.57	$4.06
Common and potential common shares:	'	'	'	'
Weighted average common shares outstanding	86.1	89.9	86.1	90.1
Assumed purchase of common shares for treasury	-3.3	-4.5	-3.4	-4.4
Assumed conversion of the CODES	1.7	'	1.6	'
Common and potential common shares	89.3	91.1	89.4	91.3
Diluted earnings per share:	'	'	'	'
Net income	$1.53	$1.92	$3.43	$4.01
Stock Options [Member]	'	'	'	'
Common and potential common shares:	'	'	'	'
Common and potential common shares	2.9	3.6	3.2	3.5
Unvested Restricted Stock Awards [Member]	'	'	'	'
Common and potential common shares:	'	'	'	'
Common and potential common shares	1.6	1.8	1.6	1.8
Employee Stock Purchase Plan Contributions [Member]	'	'	'	'
Common and potential common shares:	'	'	'	'
Common and potential common shares	0.2	0.2	0.1	0.2
Performance Unit Awards [Member]	'	'	'	'
Common and potential common shares:	'	'	'	'
Common and potential common shares	0.1	0.1	0.2	0.1

L3_Holdings_Earnings_Per_Commo3

L-3 Holdings' Earnings Per Common Share - Reconciliation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail) (USD $)	Jun. 18, 2014
Earnings Per Share [Abstract]	'
Conversion price of L-3 Holdings' CODES	$88.71

L3_Holdings_Earnings_Per_Commo4

L-3 Holdings' Earnings Per Common Share - Additional Information (Detail)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Earnings Per Share [Abstract]	'	'	'	'
Shares excluded from computation of diluted earnings per share and employee stock purchase plan contributions	0.5	1.7	0.4	1.7

Fair_Value_Measurements_Compan

Fair Value Measurements - Company's Assets and Liabilities at Fair Value on Recurring Basis (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Level 1 [Member]	'	'
Assets	'	'
Cash equivalents	$88	$299
Derivatives (foreign currency forward contracts)	'	'
Total assets	88	299
Liabilities	'	'
Derivatives (foreign currency forward contracts)	'	'
Level 2 [Member]	'	'
Assets	'	'
Cash equivalents	'	'
Derivatives (foreign currency forward contracts)	11	6
Total assets	11	6
Liabilities	'	'
Derivatives (foreign currency forward contracts)	4	5
Level 3 [Member]	'	'
Assets	'	'
Cash equivalents	'	'
Derivatives (foreign currency forward contracts)	'	'
Total assets	'	'
Liabilities	'	'
Derivatives (foreign currency forward contracts)	'	'

Financial_Instruments_Carrying

Financial Instruments - Carrying Amounts and Estimated Fair Values of Company's Long-Term Debt and Foreign Currency Forward Contracts (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Senior Notes, Carrying Amount	$3,938	$2,941
CODES, Carrying Amount	'	689
Senior Notes, Estimated Fair Value	4,245	3,121
CODES, Estimated Fair Value	'	830
Estimated Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Foreign currency forward contracts	7	1
Carrying Amount [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Foreign currency forward contracts	$7	$1

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Notional Amounts of Company's Outstanding Foreign Currency Forward Contracts by Currency (Detail) (USD $)	Jun. 27, 2014
In Millions, unless otherwise specified
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	$389
Canadian Dollar [Member]	'
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	198
U.S. Dollar [Member]	'
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	107
Euro [Member]	'
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	71
British Pound [Member]	'
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	11
Other [Member]	'
Derivative [Line Items]	'
Notional amounts of foreign currency forward contracts	$2

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Additional Information (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified		CODES Due 2035 [Member]
Derivative [Line Items]	'	'
Fair value of embedded derivative related to the issuance of the CODES	'	$0
Estimated amount of existing losses expected to be reclassified into income within the next 12 months	($2)	'

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Location of Company's Derivative Instruments Recorded at Fair Value on Condensed Consolidated Balance Sheets (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Current Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	$2	$3
Other Current Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	2	3
Other Current Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	'	'
Other Current Liabilities [Member] | CODES Due 2035 [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	'	'
Other Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	2	2
Other Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	2	2
Other Liabilities [Member] | Foreign Currency Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	'	'
Other Liabilities [Member] | CODES Due 2035 [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, assets	'	'
Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	7	5
Other Current Assets [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	7	5
Other Current Assets [Member] | Foreign Currency Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	'	'
Other Current Assets [Member] | CODES Due 2035 [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	'	'
Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	4	1
Other Assets [Member] | Foreign Currency Forward Contracts [Member] | Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	4	1
Other Assets [Member] | Foreign Currency Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	'	'
Other Assets [Member] | CODES Due 2035 [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Total derivative instruments, liabilities	'	'

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail)	0 Months Ended						0 Months Ended
In Millions, unless otherwise specified	Jul. 01, 2013	Apr. 23, 2007	Jun. 27, 2014	31-May-12	Mar. 09, 2010	Jul. 01, 2004	Jul. 23, 2014	Jul. 23, 2014
	Plaintiff	Plaintiff	USD ($)	USD ($)	USD ($)	USD ($)	Property Damages [Member]	Business Interruption [Member]
							Subsequent Event [Member]	Subsequent Event [Member]
							EUR (€)	EUR (€)
Contingencies And Commitments [Line Items]	'	'	'	'	'	'	'	'
Kalitta Air damages, minimum	'	'	$235	'	'	'	'	'
Pre-judgment interest in Kalitta Air damages, minimum	'	'	240	'	'	'	'	'
Total damages sought	'	'	'	'	'	315	'	'
Punitive damages sought	'	'	'	'	'	150	'	'
Number of plaintiffs re-filed their complaint against ACSS	'	30	'	'	'	'	'	'
Compensatory damages	'	'	'	48	6.7	'	'	'
Number of plaintiffs released their claims against ACSS	18	'	'	'	'	'	'	'
Claims for estimated damages	'	'	'	'	'	'	€ 11	€ 35

Pension_and_Other_Postretireme2

Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Pension Plans [Member]	'	'	'	'
Components of net periodic benefit cost:	'	'	'	'
Service cost	$27	$33	$54	$65
Interest cost	37	33	73	66
Expected return on plan assets	-49	-41	-97	-83
Amortization of prior service costs (credits)	'	'	1	'
Amortization of net loss (gain)	5	21	9	43
Curtailment loss	'	'	1	'
Net periodic benefit cost	20	46	41	91
Postretirement Benefit Plans [Member]	'	'	'	'
Components of net periodic benefit cost:	'	'	'	'
Service cost	1	1	2	2
Interest cost	2	1	4	3
Expected return on plan assets	-1	-1	-2	-2
Amortization of prior service costs (credits)	'	'	-1	1
Amortization of net loss (gain)	-1	'	-1	-1
Curtailment loss	'	'	'	'
Net periodic benefit cost	$1	$1	$2	$3

Pension_and_Other_Postretireme3

Pension and Other Postretirement Benefits - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014
Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Contribution to pension plans	$48
Expected contributions to plans	49
Postretirement Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Contribution to other postretirement benefit plans	3
Expected contributions to plans	$7

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 27, 2014
Employee Restricted Equity Awards And Performance Stock Awards Vesting Activity [Line Items]	'
Exercise price	$113.67
Stock options granted	472,992
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	$20.02
Restricted Stock Units [Member]	'
Employee Restricted Equity Awards And Performance Stock Awards Vesting Activity [Line Items]	'
Vesting period	'3 years
Units granted	414,067
Weighted average grant date fair value	$113.67
Vesting period of units granted for non-employee directors	'1 year
Performance Units [Member]	'
Employee Restricted Equity Awards And Performance Stock Awards Vesting Activity [Line Items]	'
Units granted	47,467
Weighted average grant date fair value	$113.67
Length of service after grant date	'3 years
Minimum payout range	0.00%
Maximum payout range	200.00%

StockBased_Compensation_Weight

Stock-Based Compensation - Weighted Average Assumptions used in Valuation Model (Detail)	6 Months Ended
	Jun. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Expected holding period (in years)	'5 years 6 months
Expected volatility	24.40%
Expected dividend yield	2.70%
Risk-free interest rate	1.70%

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information - Supplemental Cash Flow Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]	'	'
Interest paid on outstanding debt	$86	$86
Income tax payments	104	137
Income tax refunds	$6	$16

Segment_Information_Additional

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 27, 2014
	Segment
Segment Reporting [Abstract]	'
Number of segments	4

Segment_Information_Summary_of

Segment Information - Summary of Segment Information (Detail) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

42 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

In Millions, unless otherwise specified

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Dec. 31, 2013

Jun. 27, 2014

Mar. 28, 2014

Dec. 31, 2013

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Jun. 27, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2014

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Dec. 31, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Dec. 31, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Dec. 31, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Dec. 31, 2013

Jun. 27, 2014

Dec. 31, 2013

Jun. 27, 2014

Jun. 28, 2013

Jun. 27, 2014

Jun. 28, 2013

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Operating Segments [Member]

Corporate [Member]

Corporate [Member]

Elimination of Intercompany Sales [Member]

Elimination of Intercompany Sales [Member]

Elimination of Intercompany Sales [Member]

Elimination of Intercompany Sales [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Aerospace Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Electronic Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

Communication Systems [Member]

NSS [Member]

NSS [Member]

NSS [Member]

NSS [Member]

NSS [Member]

Net Sales:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net Sales

$3,019

$3,189

$5,976

$6,386

'

($10)

($13)

($21)

$5

($3)

$12

($23)

($7)

($38)

($4)

($73)

$1,062

$1,133

$2,136

$2,324

'

$1,123

$1,162

$2,221

$2,299

'

$538

$606

$1,055

$1,181

'

$336

$333

$641

$664

'

'

'

($40)

($45)

($77)

($82)

Operating Income:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating income

239

290

525

600

'

'

'

'

'

'

'

'

'

'

'

'

39

104

132

231

'

133

127

258

244

'

48

40

98

85

'

19

19

37

40

'

'

'

'

'

'

'

Depreciation and amortization:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation and amortization

55

52

109

106

'

'

'

'

'

'

'

'

'

'

'

'

9

9

19

18

'

30

29

59

59

'

13

11

25

23

'

3

3

6

6

'

'

'

'

'

'

'

Total Assets:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Assets

$14,116

'

$14,116

'

$13,988

'

'

'

'

'

'

'

'

'

'

'

$3,133

'

$3,133

'

$3,087

$7,115

'

$7,115

'

$6,928

$2,097

'

$2,097

'

$2,130

$1,339

'

$1,339

'

$1,247

$432

$596

'

'

'

'

Employee_Severance_and_Termina2

Employee Severance and Termination Costs - Additional Information (Detail) (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Dec. 31, 2013
	Employees		Employees
Restructuring and Related Activities [Abstract]	'	'	'
Employee severance and other related termination costs	$20	$14	$29
Number of employees terminated	1,300	'	2,000
Remaining balance of employee termination costs	$16	'	$11

Employee_Severance_and_Termina3

Employee Severance and Termination Costs - Employee Severance and Other Termination Costs Incurred by Reportable Segment (Detail) (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]	'	'	'
Employee severance and other related termination costs	$20	$14	$29
Aerospace Systems [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Employee severance and other related termination costs	2	'	'
Electronic Systems [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Employee severance and other related termination costs	14	9	'
Communication Systems [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Employee severance and other related termination costs	3	4	'
NSS [Member]	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'
Employee severance and other related termination costs	$1	$1	'

Condensed_Combining_Financial_2

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014
Condensed Financial Statements, Captions [Line Items]	'
Ownership percentage held in subsidiary	100.00%
Non-Guarantor Subsidiaries [Member]	'
Condensed Financial Statements, Captions [Line Items]	'
Cumulative aggregate adjustments, net	$28

Condensed_Combining_Financial_3

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Balance Sheets (Detail) (USD $)	Jun. 27, 2014	Dec. 31, 2013	Jun. 28, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current assets:	'	'	'	'
Cash and cash equivalents	$299	$500	$328	$349
Billed receivables, net	1,059	991	'	'
Contracts in process	2,633	2,431	'	'
Other current assets	714	672	'	'
Total current assets	4,705	4,594	'	'
Goodwill	7,838	7,796	'	'
Other assets	1,573	1,598	'	'
Investment in and amounts due from consolidated subsidiaries	'	'	'	'
Total assets	14,116	13,988	'	'
Current liabilities	2,494	2,534	'	'
Amounts due to consolidated subsidiaries	'	'	'	'
Other long-term liabilities	1,705	1,768	'	'
Long-term debt	3,938	3,630	'	'
Total liabilities	8,137	7,932	'	'
L-3 shareholders' equity	5,904	5,981	'	'
Noncontrolling interests	75	75	'	'
Total equity	5,979	6,056	5,650	5,527
Total liabilities and equity	14,116	13,988	'	'
L-3 Communications Holdings, Inc. [Member]	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	'	'	'	'
Billed receivables, net	'	'	'	'
Contracts in process	'	'	'	'
Other current assets	'	'	'	'
Total current assets	'	'	'	'
Goodwill	'	'	'	'
Other assets	'	'	'	'
Investment in and amounts due from consolidated subsidiaries	5,904	6,670	'	'
Total assets	5,904	6,670	'	'
Current liabilities	'	'	'	'
Amounts due to consolidated subsidiaries	'	'	'	'
Other long-term liabilities	'	'	'	'
Long-term debt	'	689	'	'
Total liabilities	'	689	'	'
L-3 shareholders' equity	5,904	5,981	'	'
Noncontrolling interests	'	'	'	'
Total equity	5,904	5,981	'	'
Total liabilities and equity	5,904	6,670	'	'
L-3 Communications Corporation [Member]	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	92	258	120	246
Billed receivables, net	333	364	'	'
Contracts in process	998	925	'	'
Other current assets	383	344	'	'
Total current assets	1,806	1,891	'	'
Goodwill	2,307	2,307	'	'
Other assets	803	838	'	'
Investment in and amounts due from consolidated subsidiaries	7,215	6,940	'	'
Total assets	12,131	11,976	'	'
Current liabilities	894	914	'	'
Amounts due to consolidated subsidiaries	'	'	'	'
Other long-term liabilities	1,395	1,451	'	'
Long-term debt	3,938	3,630	'	'
Total liabilities	6,227	5,995	'	'
L-3 shareholders' equity	5,904	5,981	'	'
Noncontrolling interests	'	'	'	'
Total equity	5,904	5,981	'	'
Total liabilities and equity	12,131	11,976	'	'
Guarantor Subsidiaries [Member]	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	2	'	'	'
Billed receivables, net	443	401	'	'
Contracts in process	1,237	1,152	'	'
Other current assets	156	159	'	'
Total current assets	1,838	1,712	'	'
Goodwill	4,327	4,326	'	'
Other assets	528	532	'	'
Investment in and amounts due from consolidated subsidiaries	3,808	3,744	'	'
Total assets	10,501	10,314	'	'
Current liabilities	979	1,011	'	'
Amounts due to consolidated subsidiaries	'	'	'	'
Other long-term liabilities	194	193	'	'
Long-term debt	'	'	'	'
Total liabilities	1,173	1,204	'	'
L-3 shareholders' equity	9,328	9,110	'	'
Noncontrolling interests	'	'	'	'
Total equity	9,328	9,110	'	'
Total liabilities and equity	10,501	10,314	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	213	261	236	242
Billed receivables, net	283	226	'	'
Contracts in process	398	354	'	'
Other current assets	175	169	'	'
Total current assets	1,069	1,010	'	'
Goodwill	1,204	1,163	'	'
Other assets	242	228	'	'
Investment in and amounts due from consolidated subsidiaries	'	'	'	'
Total assets	2,515	2,401	'	'
Current liabilities	629	628	'	'
Amounts due to consolidated subsidiaries	387	270	'	'
Other long-term liabilities	116	124	'	'
Long-term debt	'	'	'	'
Total liabilities	1,132	1,022	'	'
L-3 shareholders' equity	1,383	1,379	'	'
Noncontrolling interests	'	'	'	'
Total equity	1,383	1,379	'	'
Total liabilities and equity	2,515	2,401	'	'
Eliminations [Member]	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	-8	-19	-28	-139
Billed receivables, net	'	'	'	'
Contracts in process	'	'	'	'
Other current assets	'	'	'	'
Total current assets	-8	-19	'	'
Goodwill	'	'	'	'
Other assets	'	'	'	'
Investment in and amounts due from consolidated subsidiaries	-16,927	-17,354	'	'
Total assets	-16,935	-17,373	'	'
Current liabilities	-8	-19	'	'
Amounts due to consolidated subsidiaries	-387	-270	'	'
Other long-term liabilities	'	'	'	'
Long-term debt	'	-689	'	'
Total liabilities	-395	-978	'	'
L-3 shareholders' equity	-16,615	-16,470	'	'
Noncontrolling interests	75	75	'	'
Total equity	-16,540	-16,395	'	'
Total liabilities and equity	($16,935)	($17,373)	'	'

Condensed_Combining_Financial_4

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Operations (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	$3,019	$3,189	$5,976	$6,386
Total cost of sales	-2,780	-2,899	-5,451	-5,786
Operating (loss) income	239	290	525	600
Interest expense	-39	-44	-82	-87
Interest and other income, net	4	7	9	10
(Loss) income before income taxes	204	253	452	523
(Provision) benefit for income taxes	-63	-77	-139	-155
Equity in net income of consolidated subsidiaries	'	'	'	'
Net income	141	176	313	368
Net income attributable to noncontrolling interests	-4	-1	-6	-2
Net income attributable to L-3	137	175	307	366
Comprehensive income attributable to L-3	169	170	321	337
L-3 Communications Holdings, Inc. [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	'	'	'	'
Total cost of sales	-14	-14	-29	-28
Operating (loss) income	-14	-14	-29	-28
Interest expense	3	-5	-2	-10
Interest and other income, net	'	'	'	'
(Loss) income before income taxes	-11	-19	-31	-38
(Provision) benefit for income taxes	3	6	9	11
Equity in net income of consolidated subsidiaries	145	188	329	393
Net income	137	175	307	366
Net income attributable to noncontrolling interests	'	'	'	'
Net income attributable to L-3	137	175	307	366
Comprehensive income attributable to L-3	169	170	321	337
L-3 Communications Corporation [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	883	992	1,746	1,935
Total cost of sales	-798	-910	-1,567	-1,771
Operating (loss) income	85	82	179	164
Interest expense	-38	-44	-81	-87
Interest and other income, net	3	3	8	6
(Loss) income before income taxes	50	41	106	83
(Provision) benefit for income taxes	-18	-16	-33	-25
Equity in net income of consolidated subsidiaries	105	150	234	308
Net income	137	175	307	366
Net income attributable to noncontrolling interests	'	'	'	'
Net income attributable to L-3	137	175	307	366
Comprehensive income attributable to L-3	169	170	321	337
Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	1,655	1,721	3,280	3,458
Total cost of sales	-1,522	-1,571	-3,033	-3,140
Operating (loss) income	103	150	247	318
Interest expense	'	'	'	'
Interest and other income, net	'	1	'	'
(Loss) income before income taxes	103	151	247	318
(Provision) benefit for income taxes	-31	-43	-76	-94
Equity in net income of consolidated subsidiaries	'	'	'	'
Net income	72	108	171	224
Net income attributable to noncontrolling interests	'	'	'	'
Net income attributable to L-3	72	108	171	224
Comprehensive income attributable to L-3	79	107	175	224
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	555	572	1,098	1,162
Total cost of sales	-504	-514	-999	-1,044
Operating (loss) income	51	58	99	118
Interest expense	-1	'	-1	'
Interest and other income, net	1	3	1	4
(Loss) income before income taxes	51	61	99	122
(Provision) benefit for income taxes	-14	-18	-30	-36
Equity in net income of consolidated subsidiaries	'	'	'	'
Net income	37	43	69	86
Net income attributable to noncontrolling interests	'	'	'	'
Net income attributable to L-3	37	43	69	86
Comprehensive income attributable to L-3	60	26	75	31
Eliminations [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Total net sales	-74	-96	-148	-169
Total cost of sales	88	110	177	197
Operating (loss) income	14	14	29	28
Interest expense	-3	5	2	10
Interest and other income, net	'	'	'	'
(Loss) income before income taxes	11	19	31	38
(Provision) benefit for income taxes	-3	-6	-9	-11
Equity in net income of consolidated subsidiaries	-250	-338	-563	-701
Net income	-242	-325	-541	-674
Net income attributable to noncontrolling interests	-4	-1	-6	-2
Net income attributable to L-3	-246	-326	-547	-676
Comprehensive income attributable to L-3	($308)	($303)	($571)	($592)

Condensed_Combining_Financial_5

Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Cash Flows (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	Jun. 28, 2013
Operating activities:	'	'
Net cash from (used in) operating activities	$215	$396
Investing activities:	'	'
Business acquisitions, net of cash acquired	-57	-1
Investments in L-3 Communications	'	'
Other investing activities	-60	-103
Net cash used in investing activities	-117	-104
Financing activities:	'	'
Proceeds from sale of senior notes	996	'
Retirement of CODES	-935	'
Common stock repurchased	-333	-248
Dividends paid on L-3 Holdings common stock	-107	-101
Dividends paid to L-3 Holdings	'	'
Investments from L-3 Holdings	'	'
Other financing activities	80	45
Net cash used in financing activities	-299	-304
Effect of foreign currency exchange rate changes on cash	'	-9
Net decrease in cash and cash equivalents	-201	-21
Cash and cash equivalents, beginning of the period	500	349
Cash and cash equivalents, end of the period	299	328
L-3 Communications Holdings, Inc. [Member]	'	'
Operating activities:	'	'
Net cash from (used in) operating activities	1,375	349
Investing activities:	'	'
Business acquisitions, net of cash acquired	'	'
Investments in L-3 Communications	-77	-37
Other investing activities	'	'
Net cash used in investing activities	-77	-37
Financing activities:	'	'
Proceeds from sale of senior notes	'	'
Retirement of CODES	-935	'
Common stock repurchased	-333	-248
Dividends paid on L-3 Holdings common stock	-107	-101
Dividends paid to L-3 Holdings	'	'
Investments from L-3 Holdings	'	'
Other financing activities	77	37
Net cash used in financing activities	-1,298	-312
Effect of foreign currency exchange rate changes on cash	'	'
Net decrease in cash and cash equivalents	'	'
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 (used in) operating activities	107	146
Investing activities:	'	'
Business acquisitions, net of cash acquired	-57	-1
Investments in L-3 Communications	'	'
Other investing activities	-25	-53
Net cash used in investing activities	-82	-54
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	-1,375	-349
Investments from L-3 Holdings	77	37
Other financing activities	111	94
Net cash used in financing activities	-191	-218
Effect of foreign currency exchange rate changes on cash	'	'
Net decrease in cash and cash equivalents	-166	-126
Cash and cash equivalents, beginning of the period	258	246
Cash and cash equivalents, end of the period	92	120
Guarantor Subsidiaries [Member]	'	'
Operating activities:	'	'
Net cash from (used in) operating activities	152	254
Investing activities:	'	'
Business acquisitions, net of cash acquired	'	'
Investments in L-3 Communications	'	'
Other investing activities	-24	-39
Net cash used in investing activities	-24	-39
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	-126	-215
Net cash used in financing activities	-126	-215
Effect of foreign currency exchange rate changes on cash	'	'
Net decrease in cash and cash equivalents	2	'
Cash and cash equivalents, beginning of the period	'	'
Cash and cash equivalents, end of the period	2	'
Non-Guarantor Subsidiaries [Member]	'	'
Operating activities:	'	'
Net cash from (used in) operating activities	3	64
Investing activities:	'	'
Business acquisitions, net of cash acquired	'	'
Investments in L-3 Communications	'	'
Other investing activities	-11	-11
Net cash used in investing activities	-11	-11
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	-40	-50
Net cash used in financing activities	-40	-50
Effect of foreign currency exchange rate changes on cash	'	-9
Net decrease in cash and cash equivalents	-48	-6
Cash and cash equivalents, beginning of the period	261	242
Cash and cash equivalents, end of the period	213	236
Eliminations [Member]	'	'
Operating activities:	'	'
Net cash from (used in) operating activities	-1,422	-417
Investing activities:	'	'
Business acquisitions, net of cash acquired	'	'
Investments in L-3 Communications	77	37
Other investing activities	'	'
Net cash used in investing activities	77	37
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	1,375	349
Investments from L-3 Holdings	-77	-37
Other financing activities	58	179
Net cash used in financing activities	1,356	491
Effect of foreign currency exchange rate changes on cash	'	'
Net decrease in cash and cash equivalents	11	111
Cash and cash equivalents, beginning of the period	-19	-139
Cash and cash equivalents, end of the period	($8)	($28)