Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Carrying amount:
Total carrying amount	$ 130,709	$ 104,709
Accumulated amortization:
Total accumulated amortization	(30,752)	(24,662)
Net amortizable intangible assets	99,957	80,047
Total other intangible assets	192,172	137,862
Licensing agreements
Accumulated amortization:
Other indefinite-lived intangible assets — FCC licenses	92,215	57,815
Television network affiliation relationships
Carrying amount:
Total carrying amount	93,944	78,844
Accumulated amortization:
Total accumulated amortization	(12,855)	(9,691)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	30,404	22,304
Accumulated amortization:
Total accumulated amortization	(15,746)	(13,138)
Other
Carrying amount:
Total carrying amount	6,361	3,561
Accumulated amortization:
Total accumulated amortization	$ (2,151)	$ (1,833)