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COMMITMENTS AND CONTINGENCIES (Details) (USD $)	1 Months Ended			0 Months Ended
	May 31, 2011 class_action_lawsuits	Sep. 30, 2013 current_litigation_matters	Jun. 30, 2011	Feb. 16, 2012 New Term Loan [Member] CoStar Group [Member] LoopNet [Member]	Feb. 16, 2012 New Revolving Credit Facility [Member] CoStar Group [Member] LoopNet [Member]
Business Acquisition [Line Items]
Debt instrument borrowing capacity				$ 175,000,000	$ 50,000,000
Term of loan (in years)				5 years	5 years
Class action lawsuits brought by alleged LoopNet stockholders (in lawsuits)	3
Memorandum of understanding in which they agreed on the terms of a settlement of litigation			$ 200,000
Number of minimum of current litigation matters (in claims)		1

X

- Definition

Minimum Number of Current Litigation Matters

+ References

No definition available.

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ 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 210.5-02.22(b))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Subparagraph b

-Article 5

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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

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- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

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-Publisher FASB

-Name Accounting Standards Codification

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