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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Useful Life of Other Purchased Intangible Assets) (Details) | 12 Months Ended
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Dec. 31, 2017
Purchased data files | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 2 years
Purchased data files | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 15 years
Acquired software and technology | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 1 year
Acquired software and technology | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 10 years
Non-compete agreements | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 1 year
Non-compete agreements | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 5 years
Proprietary database | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 6 years
Proprietary database | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 10 years
Customer relationships | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 2 years
Customer relationships | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 25 years
Trade Names | Minimum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 1 year
Trade Names | Maximum |
Finite-Lived Intangible Assets [Line Items] |
Useful Life | 15 years

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

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

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Data Type: | na
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Period Type: |

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- Details
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Data Type: | na
Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |