Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) segment item	Dec. 31, 2023 USD ($)
Summary of Significant Accounting Policies
Number of market serving	28
Number of FM radio stations	82
Number of AM radio stations	32
Number of metro signals	79
Debt securities, held to maturity | $	$ 8.8	$ 10.6
Securities at fair value | $	$ 8.8	$ 10.6
Number of Radio Markets	28
Number of operating segments | segment	1
Number of reportable segments | segment	1