Goodwill and Intangible Assets, net - Goodwill Activities (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 5,927
Balance as of September 30, 2021	5,927
HuffPost Acquisition
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2020	0
Goodwill	5,927
Balance as of September 30, 2021	$ 5,927

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
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