Goodwill and other intangible assets - Goodwill, Indefinite-Lived Intangible Assets, and Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amortizable intangible assets:
Amortizable intangible assets, accumulated amortization	$ (235,582)	$ (168,452)
Amortizable intangible assets, net	379,746
Intangible assets, gross	2,739,226	2,730,066
Intangible assets, net	2,503,644	2,561,614
Retransmission agreements
Amortizable intangible assets:
Amortizable intangible assets, gross	235,215	256,533
Amortizable intangible assets, accumulated amortization	(138,928)	(105,212)
Amortizable intangible assets, net	96,287	151,321
Network affiliation agreements
Amortizable intangible assets:
Amortizable intangible assets, gross	309,503	309,496
Amortizable intangible assets, accumulated amortization	(72,694)	(48,174)
Amortizable intangible assets, net	236,809	261,322
Other
Amortizable intangible assets:
Amortizable intangible assets, gross	70,610	73,305
Amortizable intangible assets, accumulated amortization	(23,960)	(15,066)
Amortizable intangible assets, net	46,650	58,239
Television and radio station FCC broadcast licenses
Indefinite-lived intangibles:
Television and radio station FCC broadcast licenses	$ 2,123,898	$ 2,090,732