Other Financial Data (Other Current Assets) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Apr. 04, 2015	Dec. 31, 2014
Other Current Assets [Abstract]
Costs and earnings in excess of billings	$ 367	$ 417
Tax-related refunds receivable	90us-gaap_ValueAddedTaxReceivable	103us-gaap_ValueAddedTaxReceivable
Zebra receivable for cash transferred	0	49
Other	193msi_OtherUnspecifiedCurrentAssets	171msi_OtherUnspecifiedCurrentAssets
Other current assets	650us-gaap_OtherAssetsCurrent	740us-gaap_OtherAssetsCurrent
Transferred cash balance	$ 49

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

- Definition

Disposal Group, Including Discontinued Operations, Reimbursed Cash Transferred

+ References

No definition available.

+ Details

Name:	msi_DisposalGroupIncludingDiscontinuedOperationsReimbursedCashTransferred
Namespace Prefix:	msi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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=51671739&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=51671739&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

+ Details

Name:	us-gaap_CostsInExcessOfBillingsOnUncompletedContractsOrProgramsExpectedToBeCollectedWithinOneYear
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

+ Details

Name:	us-gaap_OtherAssetsCurrent
Namespace Prefix:	us-gaap_
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

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