Note 11 - Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Aug. 07, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018
Amortization of Intangible Assets, Total		$ 20,570	$ 25,072	$ 16,596
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months					$ 15,400
Finite-Lived Intangible Assets, Amortization Expense, Year Two					12,400
Finite-Lived Intangible Assets, Amortization Expense, Year Three					8,300
Finite-Lived Intangible Assets, Amortization Expense, Year Four					4,800
Finite-Lived Intangible Assets, Amortization Expense, Year Five					$ 2,900
Goodwill, Impairment Loss		0	0	0
Proceeds from Spectrum Auction			$ 90,824
FCC [Member]
Proceeds from Spectrum Auction	$ 90,800
FCC [Member] | Broadcast Licenses [Member]
Intangible Asset Dispositions from Spectrum Auction	$ 13,100