Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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

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Amount of liabilities assumed at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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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.

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Acquisitions and Divestiture - Summary of the Allocation of the Purchase Price to the Fair Value of the Assets and Liabilities Assumed, TOPO (Details) - USD ($) $ in Thousands	Oct. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Goodwill		$ 2,937,726	$ 2,923,136	$ 2,987,294
TOPO
Assets:
Cash	$ 1,281
Fees receivable	1,402
Prepaid expenses and other assets	166
Goodwill	19,293
Finite-lived intangible assets	5,250
Total assets	27,392
Total liabilities assumed (primarily deferred revenues)	2,417
Net assets acquired	$ 24,975
TOPO \| Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets useful life	6 years
TOPO \| Content
Business Acquisition [Line Items]
Acquired finite-lived intangible assets useful life	1 year 6 months