Description of business, basis of presentation and summary of significant accounting policies - Narrative (Detail)		12 Months Ended
		Dec. 31, 2021 USD ($) segment station market	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) investment
Significant Accounting Policies [Line Items]
Number of television stations | station		64
Number of radio stations | station		2
Number of markets In which entity operates | market		51
Number of operating segments | segment		1
Number of reportable segments | segment		1
Write-offs of accounts receivable		$ 1,900,000	$ 4,700,000	$ 3,000,000
Goodwill		2,981,587,000	2,968,693,000	2,950,587,000
Gain on sale of equity investments				$ 19,700,000
Number of investments | investment				4
Investments		20,300,000	20,300,000
Equity investments, impairment loss			9,200,000
Programming expense		70,700,000	71,100,000	$ 60,800,000
Syndicated programming rights		53,100,000	47,331,000
Impairment of indefinite-lived intangible assets		$ 0	0	0
Commercial reselling agreement, term		3 years
Submission period for customers to submit payments		Our customers generally submit payments monthly, generally within 60-90 days after the month that the service was provided.
Cost of revenues	[1]	$ 1,598,759,000	1,503,287,000	1,228,237,000
Licensing Agreements
Significant Accounting Policies [Line Items]
Impairment of indefinite-lived intangible assets			1,100,000
Intangible assets acquired		897,700,000
Level 2
Significant Accounting Policies [Line Items]
Recorded gains		1,900,000		5,900,000
Equity investments, impairment loss		$ 1,900,000	9,200,000
Restricted stock
Significant Accounting Policies [Line Items]
Requisite service period		4 years
Performance share units
Significant Accounting Policies [Line Items]
Requisite service period		3 years
Cost of Sales
Significant Accounting Policies [Line Items]
Bad debt expense		$ (700,000)	8,000,000	2,400,000
Minimum | Building and Improvements
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)		10 years
Minimum | Machinery, Equipment, and Fixtures
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)		3 years
Maximum | Building and Improvements
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)		40 years
Maximum | Machinery, Equipment, and Fixtures
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)		25 years
Advertising | Selling, General and Administrative Expenses
Significant Accounting Policies [Line Items]
Cost of revenues		$ 9,800,000	$ 5,800,000	$ 9,400,000

[1] Cost of revenues exclude charges for depreciation and amortization expense, which are shown separately above.