Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Quarterly Results of Operations (Unaudited)
Net operating revenue	$ 29,145,000	$ 29,149,000	$ 29,175,000	$ 25,304,000	$ 30,125,000	$ 29,980,000	$ 29,821,000	$ 24,967,000	$ 112,773,000	$ 114,893,000	$ 108,343,000
Station operating expenses	23,329,000	22,760,000	22,407,000	21,703,000	22,888,000	22,295,000	21,786,000	20,568,000	90,199,000	87,537,000	83,245,000
Corporate G&A	3,026,000	2,852,000	2,472,000	2,616,000	2,330,000	6,667,000	2,609,000	2,694,000	10,966,000	14,300,000	10,040,000
Other operating expense (income), net	(5,000)	45,000		80,000	(17,000)	(37,000)	45,000	(5,000)	120,000	(14,000)	7,000
Operating income (loss)	2,795,000	3,492,000	4,296,000	905,000	4,924,000	1,055,000	5,381,000	1,710,000	11,488,000	13,070,000	15,051,000
Other (income) expenses:
Interest expense	43,000	44,000	43,000	43,000	34,000	32,000	32,000	32,000	173,000	130,000	284,000
Interest (income)	(414,000)	(391,000)	(347,000)	(289,000)	(223,000)	(134,000)	(49,000)	(4,000)	(1,441,000)	(410,000)	(16,000)
Other (income) expense				(119,000)	(616,000)	(34,000)		(2,000)	(119,000)	(652,000)	(634,000)
Income before income taxes	3,166,000	3,839,000	4,600,000	1,270,000	5,729,000	1,191,000	5,398,000	1,684,000	12,875,000	14,002,000	15,417,000
Income tax provision:
Current	970,000	835,000	905,000	280,000	1,475,000	730,000	1,260,000	400,000	2,990,000	3,865,000	4,065,000
Deferred	(305,000)	275,000	345,000	70,000	(25,000)	565,000	315,000	80,000	385,000	935,000	195,000
Income tax expense (benefit)	665,000	1,110,000	1,250,000	350,000	1,450,000	1,295,000	1,575,000	480,000	$ 3,375,000	$ 4,800,000	$ 4,260,000
Net income (loss)	$ 2,501,000	$ 2,729,000	$ 3,350,000	$ 920,000	$ 4,279,000	$ (104,000)	$ 3,823,000	$ 1,204,000
Basic (in dollars per share)	$ 0.40	$ 0.45	$ 0.55	$ 0.15	$ 0.70	$ (0.01)	$ 0.63	$ 0.20	$ 1.55	$ 1.52	$ 1.85
Weighted average common shares	6,030	6,032	6,032	6,028	6,013	5,961	5,952	5,948	6,045	5,973	5,917
Diluted (in dollars per share)	$ 0.40	$ 0.45	$ 0.55	$ 0.15	$ 0.70	$ (0.01)	$ 0.63	$ 0.20	$ 1.55	$ 1.52	$ 1.85
Weighted average common and common equivalent shares	6,030	6,032	6,032	6,028	6,013	5,961	5,952	5,948	6,045	5,973	5,917