Goodwill and other intangible assets - Goodwill, Indefinite-Lived Intangible Assets, and Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Amortizable intangible assets:
Amortizable intangible assets, accumulated amortization	$ (168,452)		$ (118,958)
Amortizable intangible assets, net	470,882
Intangible assets, gross	2,730,066		1,645,035
Intangible assets, net	2,561,614		1,526,077
Right-of-use assets for operating leases	103,461	$ 73,800
Retransmission agreements
Amortizable intangible assets:
Amortizable intangible assets, gross	256,533		121,594
Amortizable intangible assets, accumulated amortization	(105,212)		(79,274)
Amortizable intangible assets, net	151,321		42,320
Network affiliation agreements
Amortizable intangible assets:
Amortizable intangible assets, gross	309,496		110,390
Amortizable intangible assets, accumulated amortization	(48,174)		(30,802)
Amortizable intangible assets, net	261,322		79,588
Other
Amortizable intangible assets:
Amortizable intangible assets, gross	73,305		28,865
Amortizable intangible assets, accumulated amortization	(15,066)		(8,882)
Amortizable intangible assets, net	58,239		19,983
Television and radio station FCC broadcast licenses
Indefinite-lived intangibles:
Television station FCC licenses	2,090,732		$ 1,384,186
Adjustments for New Accounting Pronouncement
Amortizable intangible assets:
Favorable lease assets	8,100
Favorable lease assets, accumulated amortization	600
Right-of-use assets for operating leases	$ 7,500