Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash paid during the period for:
Interest	$ 253	$ 311	$ 635
Income taxes	3,450	1,099	3,893
Non-cash transactions:
Barter revenue	2,125	2,014	3,560
Barter expense	2,124	1,881	3,370
Acquisition of property and equipment		6	28
Use of treasury shares for 401(k) match	$ 221	$ 250	$ 262