Salem Media Group, Inc. Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Summary of Long-term Debt Obligations - Additional Information (Detail) - USD ($) $ in Millions		9 Months Ended
	May 19, 2017	Sep. 30, 2021	Dec. 31, 2020
Shares Issued And Outstanding [Line Items]
Weighted average interest rate		6.94%	6.65%
Minimum [Member] \| Asset-Based Revolving Credit Facility [Member]
Shares Issued And Outstanding [Line Items]
Line of credit facility, unused capacity, commitment fee percentage		0.25%
Maximum [Member] \| Asset-Based Revolving Credit Facility [Member]
Shares Issued And Outstanding [Line Items]
Line of credit facility, unused capacity, commitment fee percentage	0.375%	0.375%
6.75% Senior Secured Notes [Member]
Shares Issued And Outstanding [Line Items]
Debt instrument, face amount		$ 98.8
Debt instrument, interest rate, stated percentage	6.75%	6.75%
7.125% Senior Secured Notes [Member]
Shares Issued And Outstanding [Line Items]
Debt instrument, face amount		$ 114.7
Debt instrument, interest rate, stated percentage		7.125%