Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash paid during the period for:
Interest	$ 668	$ 751	$ 874
Income taxes	9,232	6,164	7,319
Non-cash transactions:
Barter revenue	3,877	3,863	3,844
Barter expense	3,591	3,750	3,636
Purchase of treasury shares in connection with exercise of stock options	0	3,294	0
Acquisition of property and equipment	92	48	91
Acquisition of broadcast properties	$ 0	$ 50	$ 0