Nature of Business, Interim Financial Data and Basis of Presentation (Condensed Supplemental Cash Flow) (Details) - USD ($) $ in Thousands	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Jun. 03, 2018	Sep. 30, 2017	Jun. 04, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental disclosures of non-cash flow information:
Trade revenue	$ 10,600	$ 8,700	$ 13,900	$ 19,000	$ 28,900
Successor Company
Supplemental disclosures of cash flow information:
Interest paid			27,524
Income taxes paid			5,611
Supplemental disclosures of non-cash flow information:
Trade revenue			13,870
Trade expense			13,891
Transfer of deposit from escrow - WKQX acquisition			4,750
Supplemental disclosures of non-cash reorganization items impact on changes in assets and liabilities:
Accounts receivable			0
Prepaid expenses and other current assets			0
Property and equipment			0
Other intangible assets, goodwill and other assets			0
Accounts payable, accrued expenses and other liabilities			0
Stockholders' equity			0
Reconciliation of cash and cash equivalents and restricted cash to the Condensed Consolidated Balance Sheet:
Cash and cash equivalents	53,978		53,978
Restricted cash	7,708		7,708
Total cash and cash equivalents and restricted cash	$ 61,686		$ 61,686			$ 88,351
Predecessor Company
Supplemental disclosures of cash flow information:
Interest paid				0	82,844
Income taxes paid				1,992	3,444
Supplemental disclosures of non-cash flow information:
Trade revenue				18,973	28,926
Trade expense				17,964	27,847
Transfer of deposit from escrow - WKQX acquisition				0	0
Supplemental disclosures of non-cash reorganization items impact on changes in assets and liabilities:
Accounts receivable				(11)	0
Prepaid expenses and other current assets				21,077	0
Property and equipment				(121,732)	0
Other intangible assets, goodwill and other assets				283,217	0
Accounts payable, accrued expenses and other liabilities				(36,415)	0
Long-term debt				(994,407)	0
Stockholders' equity				324,620	0
Reconciliation of cash and cash equivalents and restricted cash to the Condensed Consolidated Balance Sheet:
Cash and cash equivalents		69,431		50,046	69,431		$ 102,891
Restricted cash		7,680		38,305	7,680
Total cash and cash equivalents and restricted cash		$ 77,111		$ 88,351	$ 77,111		$ 111,890	$ 139,284