Other Financial Data (Other Current Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Current Assets [Abstract]
Costs and earnings in excess of billings	$ 417	$ 405
Tax-related deposits and refunds receivable	103us-gaap_ValueAddedTaxReceivable	107us-gaap_ValueAddedTaxReceivable
Zebra receivable for cash transferred	49	0
Other	171msi_OtherUnspecifiedCurrentAssets	123msi_OtherUnspecifiedCurrentAssets
Other current assets	$ 740us-gaap_OtherAssetsCurrent	$ 635us-gaap_OtherAssetsCurrent

Disposal Group Including Discontinued Operation Accounts Receivable

No definition available.

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

- Details

Name:	msi_OtherCurrentAssetsAbstract
Namespace Prefix:	msi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents other current assets other than specified in taxonomy.

+ References

No definition available.

+ Details

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

- Definition

Amount of receivable reflecting the cost incurred on uncompleted contracts in excess of related billings which is expected to be collected within one year or the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 35

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6802688&loc=d3e57807-111642

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 35

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6802688&loc=d3e57795-111642

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(c)(3))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph c(3)

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ 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 210.5-02.8)

-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 8

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of value added taxes due either from customers arising from sales on credit terms, or as previously overpaid to tax authorities.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant