Goodwill useful life description.

No definition available.

Name:	mrin_GoodwillUsefulLifeDescription
Namespace Prefix:	mrin_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=35744172&loc=d3e2207-128464

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4845-128472

+ Details

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

- Definition

Amount of liabilities assumed at the acquisition date.

+ References

+ Details

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

- Definition

The amount of property, plant, and equipment recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4845-128472

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=35744172&loc=d3e2207-128464

+ Details

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

- Definition

Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

+ References

+ Details

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

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_DevelopedTechnologyRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_NoncompeteAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mrin_SocialMoovMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TradeNamesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mrin_NowSpotsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Combinations - Summary of Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Residual Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Feb. 12, 2015	Dec. 31, 2014	Jun. 02, 2014
Business Acquisition [Line Items]
Goodwill	$ 19,417		$ 11,527
Minimum [Member]
Business Acquisition [Line Items]
Developed technology	2 years
Maximum [Member]
Business Acquisition [Line Items]
Developed technology	6 years
Developed technology [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Developed technology	5 years
Developed technology [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Developed technology	6 years
Customer relationships [Member]
Business Acquisition [Line Items]
Developed technology	4 years
Non-compete agreements and tradename [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Developed technology	2 years
Non-compete agreements and tradename [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Developed technology	3 years
SocialMoov [Member]
Business Acquisition [Line Items]
Tangible assets acquired	$ 2,607
Liabilities assumed (see Note 8)	(3,440)	$ (1,953)
Goodwill	7,888	$ 7,888
Total purchase price	$ 13,195
Goodwill	Indefinite
SocialMoov [Member] \| Developed technology [Member]
Business Acquisition [Line Items]
Developed technology	$ 3,800
Developed technology	5 years
SocialMoov [Member] \| Customer relationships [Member]
Business Acquisition [Line Items]
Developed technology	$ 2,080
Developed technology	4 years
SocialMoov [Member] \| Tradename [Member]
Business Acquisition [Line Items]
Developed technology	$ 260
Developed technology	3 years
NowSpots, Inc. [Member]
Business Acquisition [Line Items]
Tangible assets acquired	$ 1,493
Liabilities assumed (see Note 8)	(5,082)			$ (4,713)
Goodwill	11,529			$ 11,529
Total purchase price	$ 16,470
Goodwill	Indefinite
NowSpots, Inc. [Member] \| Developed technology [Member]
Business Acquisition [Line Items]
Developed technology	$ 6,110
Developed technology	6 years
NowSpots, Inc. [Member] \| Customer relationships [Member]
Business Acquisition [Line Items]
Developed technology	$ 1,290
Developed technology	4 years
NowSpots, Inc. [Member] \| Non-compete agreements and tradename [Member]
Business Acquisition [Line Items]
Developed technology	$ 1,130
NowSpots, Inc. [Member] \| Non-compete agreements and tradename [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Developed technology	2 years
NowSpots, Inc. [Member] \| Non-compete agreements and tradename [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Developed technology	3 years