Share-Based Compensation Plans (Schedule Of Compensation Expense) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Apr. 04, 2015	Mar. 29, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense included in Operating earnings	$ 21	$ 28
Tax benefit	7	9
Share-based compensation expense, net of tax	14	19
Decrease in basic earnings per share (US$ per share)	$ (0.07)	$ (0.07)
Decrease in diluted earnings per share (US$ per share)	$ (0.06)	$ (0.07)
Share-based compensation expense in discontinued operations	0	8
Costs of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense included in Operating earnings	3	3
Selling, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense included in Operating earnings	13	17
Research and development expenditures
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense included in Operating earnings	$ 5	$ 8

Discontinued Operations, Share-Based Compensation Expense

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

This element represents the increase (decrease) in basic earnings per share attributable to share-based compensation expense.

+ References

No definition available.

+ Details

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Namespace Prefix:	msi_
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Period Type:	duration

- Definition

This element represents the increase (decrease) in diluted earnings per share attributable to share-based compensation expense.

+ References

No definition available.

+ Details

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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 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: 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 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=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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Period Type:	duration

- 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=6415400&loc=d3e5070-113901

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