Note 10 - Goodwill and Intangible Assets - Changes in Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill	$ 485,318	$ 423,236
Goodwill, Acquired During Period	125,782	72,296	$ 48,300
Goodwill		(10,214)
Goodwill	611,100	485,318	423,236
Broadcast licenses	1,340,305
Broadcast licenses		0
Broadcast licenses	1,530,703	1,340,305
Finite-lived intangible assets	56,250	53,280
Finite-lived Intangible Assets Acquired	42,606	19,566
Finite-lived intangible assets	(25,072)	(16,596)	(11,982)
Finite-lived intangible assets	73,784	56,250	53,280
Total intangible assets net of accumulated amortization	1,881,873	1,591,142
Total intangible assets net of accumulated amortization	371,891	342,897
Total intangible assets net of accumulated amortization	(13,105)	(35,570)
Total intangible assets net of accumulated amortization	2,215,587	1,881,873	1,591,142
Broadcast Licenses [Member]
Broadcast licenses	1,340,305	1,114,626
Broadcast licenses	203,503	251,035
Broadcast licenses	(13,105)	(25,356)
Broadcast licenses	$ 1,530,703	$ 1,340,305	$ 1,114,626