Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Carrying amount:
Total carrying amount	$ 331,467	$ 318,967
Accumulated amortization:
Total accumulated amortization	(67,386)	(43,595)
Net amortizable intangible assets	264,081	275,372
Total other intangible assets	467,896	479,187
FCC licenses
Accumulated amortization:
Other indefinite-lived intangible assets - FCC licenses	203,815	203,815
Television network affiliation relationships
Carrying amount:
Total carrying amount	248,444	248,444
Accumulated amortization:
Total accumulated amortization	(37,019)	(24,590)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	56,100	56,100
Accumulated amortization:
Total accumulated amortization	(24,380)	(17,092)
Other intangible assets
Carrying amount:
Total carrying amount	26,923	14,423
Accumulated amortization:
Total accumulated amortization	$ (5,987)	$ (1,913)