Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 32,465	$ 30,013	$ 95,359	$ 89,047
Operating expenses:
Direct, exclusive of depreciation and amortization	12,109	11,780	35,269	35,685
Selling, general and administrative, exclusive of depreciation and amortization	8,706	7,679	24,732	23,486
Depreciation and amortization	1,430	1,388	4,285	3,996
Total operating expenses	22,245	20,847	64,286	63,167
Operating income	10,220	9,166	31,073	25,880
Other income (expense):
Interest income	10	3	24	57
Interest expense	(510)	(544)	(1,613)	(990)
Other, net	89	(242)	(330)	222
Total other (expense) income	(411)	(783)	(1,919)	(711)
Income before income taxes	9,809	8,383	29,154	25,169
Provision for income taxes	1,690	1,391	5,446	2,923
Net income	$ 8,119	6,992	$ 23,708	22,246
Denominator for net income per share - basic:
Basic earnings per share (in dollars per share)	$ 0.33		$ 0.95
Numerator for net income per share - diluted:
Diluted earnings per share (in dollars per share)	$ 0.31		$ 0.92
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in shares)	24,827		24,794
Weighted average shares and share equivalents outstanding, diluted (in shares)	25,741		25,624
Common Class A [Member]
Other income (expense):
Net income		$ 6,992		$ 17,622
Denominator for net income per share - basic:
Basic earnings per share (in dollars per share)		$ 0.28		$ 0.76
Numerator for net income per share - diluted:
Diluted earnings per share (in dollars per share)		$ 0.27		$ 0.73
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in shares)		24,671		23,184
Weighted average shares and share equivalents outstanding, diluted (in shares)		25,526		24,083
Common Class B [Member]
Other income (expense):
Net income				$ 4,624
Denominator for net income per share - basic:
Basic earnings per share (in dollars per share)				$ 1.31
Numerator for net income per share - diluted:
Diluted earnings per share (in dollars per share)				$ 1.27
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in shares)				3,527
Weighted average shares and share equivalents outstanding, diluted (in shares)				3,628