Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Carrying amount:
Total carrying amount	$ 331,467	$ 318,967
Accumulated amortization:
Total accumulated amortization	(61,693)	(43,595)
Net amortizable intangible assets	269,774	275,372
Total other intangible assets	473,589	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	(33,911)	(24,590)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	56,100	56,100
Accumulated amortization:
Total accumulated amortization	(22,976)	(17,092)
Other
Carrying amount:
Total carrying amount	26,923	14,423
Accumulated amortization:
Total accumulated amortization	$ (4,806)	$ (1,913)