Acquisitions and Dispositions - Purchase price allocation for the assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Dec. 03, 2021	Feb. 16, 2021
Business Acquisition [Line Items]
Goodwill	$ 194,079	$ 194,881	$ 188,600
C Acquisition
Business Acquisition [Line Items]
Cash			2,881
Accounts receivable			22,592
Prepaid and other current assets			18,108
Property and equipment			317
Intangible assets			119,100
Goodwill			188,589
Accounts payable			(2,661)
Accrued expenses			(13,229)
Accrued compensation			(12,518)
Deferred revenue			(5,903)
Deferred tax liabilities			(21,642)
Other liabilities			(1,468)
Total consideration for Complex Networks			294,166
C Acquisition | Preliminary
Business Acquisition [Line Items]
Cash			2,881
Accounts receivable			22,581
Prepaid and other current assets			17,827
Property and equipment			332
Intangible assets			119,100
Goodwill			189,391
Accounts payable			(2,661)
Accrued expenses			(12,319)
Accrued compensation			(12,867)
Deferred revenue			(5,855)
Deferred tax liabilities			(22,776)
Other liabilities			(1,468)
Total consideration for Complex Networks			294,166
C Acquisition | Measurement Period Adjustments
Business Acquisition [Line Items]
Accounts receivable			11
Prepaid and other current assets			281
Property and equipment			(15)
Goodwill			(802)
Accrued expenses			(910)
Accrued compensation			349
Deferred revenue			(48)
Deferred tax liabilities			$ 1,134
HuffPost
Business Acquisition [Line Items]
Cash and cash equivalents		5,513
Accounts receivable		3,383
Prepaid and other current assets		611
Deferred tax assets		131
Property and equipment		620
Intangible assets		19,500
Goodwill		5,490		$ 5,500
Accounts payable		(1,410)
Accrued expenses		(4,249)
Deferred tax liabilities		(3,829)
Other liabilities		(63)
Noncontrolling interests		(2,123)
Total consideration for HuffPost		23,574
HuffPost | Preliminary
Business Acquisition [Line Items]
Cash and cash equivalents				5,513
Accounts receivable				3,383
Prepaid and other current assets				611
Deferred tax assets				116
Property and equipment				620
Intangible assets				19,500
Goodwill				5,927
Accounts payable				(1,410)
Accrued expenses				(4,249)
Deferred tax liabilities				(4,251)
Other liabilities				(63)
Noncontrolling interests				(2,123)
Total consideration for HuffPost				$ 23,574
HuffPost | Measurement Period Adjustments
Business Acquisition [Line Items]
Deferred tax assets		15
Goodwill		(437)
Deferred tax liabilities		$ 422