Discontinued Operations (Details Textual) - USD ($)					3 Months Ended	12 Months Ended
	Nov. 03, 2017	Oct. 05, 2017	Sep. 02, 2017	May 09, 2017	Sep. 30, 2017	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	[1]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration				$ 23,000,000
Disposal Group, Including Discontinued Operation, Income Tax Rate						41.00%
Discontinued Operation, Disposal of Discontinued Operation, Transaction Costs						$ 50,000
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net			$ 1,300,000	3,400,000
Payments to Acquire Businesses, Net of Cash Acquired			$ 24,200,000	24,200,000
Revolving Credit Facility [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of Lines of Credit	$ 5,000,000	$ 5,287,000
Joplin, Missouri and Victoria, Texas Television Stations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Total				29,900,000
Disposal Group, Including Discontinued Operation, Consideration				66,600,000
Discontinued Operation, Disposal of Discontinued Operation, Transaction Costs				500,000
Proceeds from Divestiture of Businesses, Net of Cash Divested				$ 69,500,000		69,528,000	[1]	$ 0	[1]	$ 0
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net						$ 0		$ 3,868,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal					$ 50,800,000

[1] Net proceeds from the sale of the television stations reflect the sales price of $66.6 million, the sale of accounts receivable of approximately $3.4 million, offset by certain closing adjustments and transactional costs of approximately $500 thousand.