RELATED PARTY TRANSACTIONS (Details Textual) - USD ($)	1 Months Ended	12 Months Ended
	Nov. 20, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Operating Leases, Rent Expense		$ 15,500,000	$ 15,300,000	$ 14,800,000
Related Party Annual Payments For Insurance Premiums			386,000
Net Assets		2,800,000	2,600,000	2,500,000
Business Combination, Consideration Transferred		4,043,000	10,120,000
Related Party Transaction, Amounts of Transaction		500,000
Split-Dollar Life Insurance [Member]
Related Party Transaction [Line Items]
Business Combination, Consideration Transferred		1,400,000	1,000,000	600,000
Trust [Member] | Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Operating Leases, Rent Expense		191,000	185,000	180,000
Know the Truth [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		1,200,000	400,000	400,000
Accounts Receivable, Related Parties		700,000	200,000
Chairman And Chief Executive Officer [Member] | Land and Building [Member]
Related Party Transaction [Line Items]
Operating Leases, Rent Expense		1,500,000	1,500,000	1,300,000
Truth For Life [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		2,100,000	2,200,000	2,200,000
Accounts Receivable, Related Parties		200,000	200,000
Edward G. Atsinger III, Chief Executive Officer and Director [Member]
Related Party Transaction [Line Items]
Operating Leases, Rent Expense		217,000	301,000	$ 133,000
The Truth Network [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			11,000
Accounts Receivable, Related Parties		3,000	$ 4,000
AM 570, LLC [Member]
Related Party Transaction [Line Items]
Business Combination, Consideration Transferred	$ 600,000
Delmarva Educational Association Corporation [Member]
Related Party Transaction [Line Items]
Business Combination, Consideration Transferred		$ 21,000