This line item represents the allocated share based compensation expense net of tax from continuing operations.

No definition available.

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- Definition

This line item represents the allocated share based compensation expense net of tax from discontinued operations.

+ References

No definition available.

+ Details

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- Definition

Each share of common stock issued under a full value award (awards other than stock options or stock appreciation rights) will be counted as 2.6 shares for purposes of monitoring the share limit.

+ References

No definition available.

+ Details

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- Definition

The additional maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

No definition available.

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- References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The amount of expense, net of income tax, recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

No definition available.

+ Details

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Data Type:	xbrli:sharesItemType
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Stock-Based Compensation, Stock-Based Compensation Plans (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 03, 2016	Feb. 23, 2016	Feb. 22, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of L-3 Holdings common stock available to be awarded (in shares)					4,260	3,690
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]
Stock based compensation	$ 57	$ 49	$ 49
Income taxes	(12)	(18)	(18)
Total after income taxes	45	31	31
Less: Stock-based compensation recorded in discontinued operations, net of income taxes	1	1	1
Stock-based compensation recorded in continuing operations, net of income taxes	44	30	30
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]
Stock based compensation	7	10	9
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]
Stock based compensation	43	35	38
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]
Stock based compensation	$ 7	$ 4	$ 2
2008 Long Term Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of additional shares authorized for issuance under the amendment (in shares)				6,800
Number of shares authorized for issuance under the amendment (in shares)				26,000
Maximum number of shares of L-3 Holdings common stock may be issued pursuant to "full value" awards under the amendment (in shares)	7,900