Summary of Significant Accounting Policies (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) item shares	Sep. 30, 2022 shares	Sep. 30, 2023 USD ($) item segment shares	Sep. 30, 2022 shares	Dec. 31, 2022 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of market serving | item	27		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	0	0
Debt securities, held to maturity | $	$ 10,500,000		$ 10,500,000		$ 10,100,000
Securities at fair value | $	10,500,000		10,500,000		10,000,000.0
Allowance for doubtful accounts receivable | $	$ 497,000		$ 497,000		$ 519,000
Number of Radio Markets | item			27
Number of operating segments | segment			1
Number of reportable segments | segment			1