Acquisitions and Dispositions - Purchase price allocation for the assets acquired and liabilities assumed (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Dec. 03, 2021	Feb. 16, 2021
Business Acquisition [Line Items]
Goodwill	$ 194,050,000	$ 194,881,000	$ 188,600,000
C Acquisition
Business Acquisition [Line Items]
Cash			2,881
Accounts receivable			22,592
Prepaid and other current assets			17,827
Property and equipment			317
Intangible assets			119,100
Goodwill			188,560
Accounts payable			(2,661)
Accrued expenses			(11,833)
Accrued compensation			(12,518)
Deferred revenue			(5,855)
Deferred tax liabilities			(22,776)
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
Property and equipment			(15)
Goodwill			(831)
Accrued expenses			486
Accrued compensation			$ 349
HuffPost
Business Acquisition [Line Items]
Cash and cash equivalents				$ 5,513,000
Accounts receivable				3,383,000
Prepaid and other current assets				611,000
Deferred tax assets				131,000
Property and equipment				620,000
Intangible assets				19,500,000
Goodwill				5,500,000
Goodwill				5,490,000
Accounts payable				(1,410,000)
Accrued expenses				(4,249,000)
Deferred tax liabilities				(3,829,000)
Other liabilities				(63,000)
Noncontrolling interests				(2,123,000)
Total consideration for Complex Networks				23,574,000
HuffPost | Preliminary
Business Acquisition [Line Items]
Cash and cash equivalents				5,513,000
Accounts receivable				3,383,000
Prepaid and other current assets				611,000
Deferred tax assets				116,000
Property and equipment				620,000
Intangible assets				19,500,000
Goodwill				5,927,000
Accounts payable				(1,410,000)
Accrued expenses				(4,249,000)
Deferred tax liabilities				(4,251,000)
Other liabilities				(63,000)
Noncontrolling interests				(2,123,000)
Total consideration for Complex Networks				23,574,000
HuffPost | Measurement Period Adjustments
Business Acquisition [Line Items]
Deferred tax assets				15,000
Goodwill				(437,000)
Deferred tax liabilities				$ 422,000