Long-term Customer Financing and Sales Of Receivables (Long-Term Customer Financing) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Long-Term Customer Financing And Sales Of Receivables [Abstract]
Long-term receivables	$ 101	$ 177
Less allowance for losses	0	(10)
Long-term receivables, net	101	167
Less current portion	(41)	(130)
Non-current long-term receivables, net	$ 60	$ 37

Name:	msi_LongTermCustomerFinancingAndSalesOfReceivablesAbstract
Namespace Prefix:	msi_
Data Type:	xbrli:stringItemType
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Period Type:	duration

This element represents the gross amount of receivables with payment terms greater than 12 months, long-term loans and lease receivables under sales-type leases.

+ References

No definition available.

+ Details

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

- Definition

Amount due from customers for trade receivables with payment terms greater than 12 months, long-term loans and lease receivables under sales-type leases, net of a valuation allowance.

+ References

No definition available.

+ Details

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

- Definition

This element represents the net amount current portion of long term receivables which consist of trade receivables, long-term loans and lease receivables under sales-type leases.

+ References

No definition available.

+ Details

Name:	msi_LongTermReceivableLoansAndLeaseNetCurrent
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

+ Details

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

- Definition

A valuation allowance for receivables due to an Entity for more than one year from the balance sheet date that are expected to be uncollectible.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5074-111524

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

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 210.5-02.17)

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

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivableNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant