SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Voluntary Filing Under Chapter 11 (Narrative) (Details) $ in Thousands	Feb. 28, 2019 USD ($) claim	Jan. 22, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 28, 2018 USD ($)	Dec. 31, 2017 USD ($)
Subsequent Event [Line Items]
Stated interest rate			8.75%
Total debt			$ 20,472,917		$ 20,649,181
Subsequent Event
Subsequent Event [Line Items]
Bankruptcy claims, number claims filed | claim	4,300
Bankruptcy claims, amount of claims filed	$ 808,400,000
Bankruptcy claims, number of claims expunged by bankruptcy court | claim	1,500
Bankruptcy claims, amount of claims expunged by bankruptcy court	$ 7,000,000
Bankruptcy claims, number of filed claims likely to be denied | claim	180
Bankruptcy claims, amount of filed claims likely to be denied	$ 9,900
DIP Facility | iHeartCommunications, Inc.
Subsequent Event [Line Items]
Total debt				$ 16,000,000
DIP Facility | iHeartCommunications, Inc. | Subsequent Event
Subsequent Event [Line Items]
Total debt		$ 5,750,000
Senior Notes | Legacy Notes Due 2018 | iHeartCommunications
Subsequent Event [Line Items]
Stated interest rate			6.875%
Senior Notes | Legacy Notes Due 2027 | iHeartCommunications
Subsequent Event [Line Items]
Stated interest rate			7.25%
Senior Notes | Legacy Notes Due 2016 | iHeartCommunications
Subsequent Event [Line Items]
Stated interest rate			5.50%