Other matters - Narrative (Detail) $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 02, 2020 USD ($) market	Jan. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Proceeds from sale of minority ownership interest	$ 14,000			$ 0	$ 14,000	$ 0
Subsequent Event | Intangible Contract Asset
Commitments and Contingencies Disclosure [Line Items]
Amortizable intangible assets, gross		$ 20,800
Intangible asset useful life		2 years
Subsequent Event | Forecast
Commitments and Contingencies Disclosure [Line Items]
Debt instrument, amendment gain			$ 20,800
Gray Television
Commitments and Contingencies Disclosure [Line Items]
Number of television markets | market	113
One Major Customer | Sales Revenue | Customer Concentration Risk
Commitments and Contingencies Disclosure [Line Items]
Revenues					393,400
Two Customers | Sales Revenue | Customer Concentration Risk
Commitments and Contingencies Disclosure [Line Items]
Revenues				410,800	399,700
Customer A | Sales Revenue | Customer Concentration Risk
Commitments and Contingencies Disclosure [Line Items]
Revenues						270,300
Customer B | Sales Revenue | Customer Concentration Risk
Commitments and Contingencies Disclosure [Line Items]
Revenues						251,200
Programming Contracts
Commitments and Contingencies Disclosure [Line Items]
Purchase commitments under contract				1,350,000
Equity And Debt Investment
Commitments and Contingencies Disclosure [Line Items]
Expenses incurred with related party				80,300	55,100	$ 34,300
Accounts payable and accrued liabilities with related party				$ 8,900	$ 13,500