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

Recent Transactions - Divestitures - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended
	Mar. 18, 2021	Feb. 05, 2020	Mar. 31, 2021	Mar. 31, 2020
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Proceeds from sale of intangible assets			$ 3,501	$ 2
Radio Stations [member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Proceeds from sale of intangible assets	$ 3,500	$ 4,000	3,200
Pretax loss on sale of assets	$ 1,400		300
Radio Stations [member] \| Maximum [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Pretax loss on sale of assets			$ 1,700