Expiry period of contingent gains associated with outstanding escrows.

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Number of customers.

+ References

No definition available.

+ Details

Name:	acta_NumberOfCustomers
Namespace Prefix:	acta_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of sources of revenues.

+ References

No definition available.

+ Details

Name:	acta_NumberOfSourcesOfRevenues
Namespace Prefix:	acta_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of maintenance and support.

+ References

No definition available.

+ Details

Name:	acta_PeriodOfMaintenanceAndSupport
Namespace Prefix:	acta_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Subscription revenue term maximum.

+ References

No definition available.

+ Details

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Namespace Prefix:	acta_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Subscription revenue term minimum.

+ References

No definition available.

+ Details

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13531-108611

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of cash paid for interest during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

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

+ Details

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

- Details

Name:	dei_LegalEntityAxis=acta_ChannelIntelligenceMember
Namespace Prefix:
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- Details

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- Details

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- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
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Period Type:

- Details

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Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]
Long-term restricted cash	$ 0.4	$ 0
Interest paid	1.0us-gaap_InterestPaid	1.2us-gaap_InterestPaid
Taxes paid	2.0us-gaap_IncomeTaxesPaid	0.3us-gaap_IncomeTaxesPaid	0.1us-gaap_IncomeTaxesPaid
Expiry period of contingent gains associated with outstanding escrows	2015
Actua's Consolidated Revenue
Significant Accounting Policies [Line Items]
Number of customers represented for more than 10% of consolidated revenue	0	0	0
Channel Intelligence
Significant Accounting Policies [Line Items]
Proceeds from escrow releases	3.2
Maximum
Significant Accounting Policies [Line Items]
Interest paid			$ 0.1
MSDSonline One
Significant Accounting Policies [Line Items]
Number of sources of revenues	2
Maintenance and customer support fees, contract life	1 year
FolioDynamix
Significant Accounting Policies [Line Items]
Initial subscription arrangement, Minimum	3 years
Initial subscription arrangement, Maximum	5 years
FolioDynamix \| Sales Revenue, Net
Significant Accounting Policies [Line Items]
Percentage of consolidated deferred revenue	10.00%