Other Financial Data (Other Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Assets [Abstract]
Intangible assets	$ 23us-gaap_FiniteLivedIntangibleAssetsNet	$ 6us-gaap_FiniteLivedIntangibleAssetsNet
Long-term receivables	31us-gaap_AccountsReceivableNetNoncurrent	1us-gaap_AccountsReceivableNetNoncurrent
Other	91msi_OtherUnspecifiedAssets	82msi_OtherUnspecifiedAssets
Other assets	$ 145us-gaap_OtherAssetsNoncurrent	$ 89us-gaap_OtherAssetsNoncurrent

The aggregate carrying amount as of the balance sheet date of noncurrent assets not separately disclosed in the financial statements or notes thereto.

No definition available.

+ Details

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Namespace Prefix:	msi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount due from customers or clients, more than one year from the balance sheet date, for goods or services that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Article 5

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

+ References

+ Details

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Period Type:	instant

- Details

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