Note 2 - Acquisitions and Dispositions - Purchase Consideration in Acquisition (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 01, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Base purchase price			$ 472,500
Purchase price adjustment			574
Business Combination, Consideration Transferred			473,074
Cash consideration received from sale of Schurz Radio Stations			(16,000)
Net adjusted purchase price allocated to assets acquired and liabilities assumed			457,074
Non-cash consideration received			(30,000)
Cash consideration received		$ 0	(11,200)	$ 0
Net consideration - the Schurz Acquisition and Related Transactions			415,874
WBXX Acquisition [Member]
Base purchase price			30,000
Purchase price adjustment			0
Business Combination, Consideration Transferred			30,000
Cash consideration received from sale of Schurz Radio Stations			0
Net adjusted purchase price allocated to assets acquired and liabilities assumed			30,000
Non-cash consideration received			0
Cash consideration received			0
Net consideration - the Schurz Acquisition and Related Transactions			30,000
Schurz Acquisition and the Acquisition of WLUC-TV [Member]
Base purchase price			442,500
Purchase price adjustment			574
Business Combination, Consideration Transferred			443,074
Cash consideration received from sale of Schurz Radio Stations			(16,000)
Net adjusted purchase price allocated to assets acquired and liabilities assumed			427,074
Non-cash consideration received			0
Cash consideration received			0
Net consideration - the Schurz Acquisition and Related Transactions			427,074
KAKE-TV [Member]
Base purchase price			0
Purchase price adjustment			0
Business Combination, Consideration Transferred	$ 443,100		0
Cash consideration received from sale of Schurz Radio Stations			0
Net adjusted purchase price allocated to assets acquired and liabilities assumed			0
Non-cash consideration received			(30,000)
Cash consideration received	$ (11,200)		(11,200)
Net consideration - the Schurz Acquisition and Related Transactions			$ (41,200)