Summary of Significant Accounting Policies (Narrative) (Details)					3 Months Ended
	Mar. 01, 2022 USD ($) $ / shares	Dec. 14, 2021 USD ($) $ / shares	Sep. 28, 2021 USD ($) $ / shares	Jun. 18, 2021 USD ($) $ / shares	Mar. 31, 2022 USD ($) segment item $ / shares shares	Mar. 31, 2021 $ / shares shares	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number Of FM Radio Stations | item					79
Number Of AM Radio Stations					35
Number Of Metro Signals					80
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					0	0
Number of reportable segments | segment					1
Dividends Payable, Date Declared	Mar. 01, 2022	Dec. 14, 2021	Sep. 28, 2021	Jun. 18, 2021
Dividends declared per share | $ / shares					$ 0.16	$ 0
Dividends | $	$ 970,000	$ 3,990,000	$ 960,000	$ 960,000
Dividends Payable, Date to be Paid	Apr. 08, 2022	Jan. 14, 2022	Oct. 22, 2021	Jul. 16, 2021
Dividends Payable, Date of Record	Mar. 21, 2022	Dec. 27, 2021	Oct. 08, 2021	Jun. 30, 2020
Number Of Market Serving | item					27
Operating Lease, Right-of-Use Asset | $					$ 5,800,000		$ 6,100,000
Number of operating segments | segment					1
Operating Lease, Liability | $					$ 6,085,000		6,400,000
Allowance for doubtful accounts receivable | $					$ 467,000		$ 469,000
Number of Radio Markets | item					27
Customer relationships [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life					3 years
Class A Common Stock
Summary Of Significant Accounting Policies [Line Items]
Dividends declared per share | $ / shares	$ 0.16	$ 0.16	$ 0.16	$ 0.16
Class B Common Stock
Summary Of Significant Accounting Policies [Line Items]
Dividends declared per share | $ / shares	$ 0.16	0.16	$ 0.16	$ 0.16
Common Class A and Common Class B
Summary Of Significant Accounting Policies [Line Items]
Dividends declared per share | $ / shares		$ 0.50