Summary of Significant Accounting Policies (Narrative) (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) segment item shares	Mar. 31, 2022 shares	Dec. 31, 2022 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of market serving | item	27
Number of FM radio stations | item	79
Number of AM radio stations	33
Number of metro signals	80
Antidilutive securities excluded from computation of earnings per share, amount | shares	0	0
Securities at fair value | $	$ 10,200,000		$ 10,000,000
Debt securities, held to maturity | $	10,200,000		10,100,000
Allowance for doubtful accounts receivable | $	$ 526,000		$ 519,000
Number of Radio Markets | item	27
Number of operating segments | segment	1
Number of reportable segments | segment	1