Goodwill and Other Intangible Assets - Summary of other intangible assets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Carrying amount:
Total carrying amount	$ 138,409	$ 104,709
Accumulated amortization:
Total accumulated amortization	(28,481)	(24,662)
Net amortizable intangible assets	109,928	80,047
Total other intangible assets	189,143	137,862
Licensing agreements
Accumulated amortization:
Other indefinite-lived intangible assets — FCC licenses	79,215	57,815
Television network affiliation relationships
Carrying amount:
Total carrying amount	87,944	78,844
Accumulated amortization:
Total accumulated amortization	(11,666)	(9,691)
Customer lists and advertiser relationships
Carrying amount:
Total carrying amount	30,404	22,304
Accumulated amortization:
Total accumulated amortization	(14,770)	(13,138)
Retransmission agreements
Carrying amount:
Total carrying amount	14,700	0
Accumulated amortization:
Total accumulated amortization	0	0
Other
Carrying amount:
Total carrying amount	5,361	3,561
Accumulated amortization:
Total accumulated amortization	$ (2,045)	$ (1,833)