Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying amount:
Total carrying amount	$ 824,141	$ 823,500
Accumulated amortization:
Total accumulated amortization	(176,722)	(148,740)
Net amortizable intangible assets	647,419	674,760
Indefinite-lived intangible assets — FCC licenses	385,915	385,915
Total other intangible assets	1,033,334	1,060,675
Television network affiliation relationships
Carrying amount:
Total carrying amount	616,244	616,244
Accumulated amortization:
Total accumulated amortization	(98,565)	(82,917)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	104,300	104,300
Accumulated amortization:
Total accumulated amortization	(47,703)	(42,012)
Other
Carrying amount:
Total carrying amount	103,597	102,956
Accumulated amortization:
Total accumulated amortization	$ (30,454)	$ (23,811)