Revenue Recognition (Revenue from Non-Exclusive Data Licenses) (Details)	3 Months Ended
Mar. 31, 2017
Minimum [Member]
Revenue from External Customer
Payment terms of non-exclusive license contracts	30 days
Maximum [Member]
Revenue from External Customer
Payment terms of non-exclusive license contracts	12 months

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.

No definition available.

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Balance Type:	na
Period Type:	duration