Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Carrying amount:
Total carrying amount	$ 837,225	$ 837,100
Accumulated amortization:
Total accumulated amortization	(175,349)	(161,224)
Net amortizable intangible assets	661,876	675,876
Indefinite-lived intangible assets — FCC licenses	385,915	385,915
Total other intangible assets	1,047,791	1,061,791
Television network affiliation relationships
Carrying amount:
Total carrying amount	616,244	616,244
Accumulated amortization:
Total accumulated amortization	(90,872)	(82,917)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	111,700	111,700
Accumulated amortization:
Total accumulated amortization	(51,419)	(48,586)
Other
Carrying amount:
Total carrying amount	109,281	109,156
Accumulated amortization:
Total accumulated amortization	$ (33,058)	$ (29,721)