Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Common Class A [Member]
Other income (expense):
Net income	$ 2,345	$ 2,060	$ 7,339	$ 5,825
Basic Earnings Per Share:
Basic earnings per share (in dollars per share)	$ 0.11	$ 0.10	$ 0.35	$ 0.28
Diluted Earnings Per Share:
Diluted earnings per share (in dollars per share)	0.11	0.10	0.35	0.28
Dividends Per Share of Common Stock:
Dividends per share (in dollars per share)	$ 0.08	$ 0.06	$ 0.24	$ 0.18
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in shares)	20,716	20,726	20,712	20,769
Weighted average shares and share equivalents outstanding, diluted (in shares)	21,068	20,937	21,017	21,002
Common Class B [Member]
Other income (expense):
Net income	$ 2,384	$ 2,078	$ 7,454	$ 5,858
Basic Earnings Per Share:
Basic earnings per share (in dollars per share)	$ 0.67	$ 0.59	$ 2.11	$ 1.67
Diluted Earnings Per Share:
Diluted earnings per share (in dollars per share)	0.66	0.59	2.08	1.65
Dividends Per Share of Common Stock:
Dividends per share (in dollars per share)	$ 0.48	$ 0.36	$ 1.44	$ 1.08
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in shares)	3,511	3,478	3,503	3,478
Weighted average shares and share equivalents outstanding, diluted (in shares)	3,556	3,521	3,557	3,522
Revenue	$ 27,032	$ 25,244	$ 81,016	$ 75,979
Direct	11,468	11,006	33,741	33,246
Selling, general and administrative	7,139	6,620	21,766	20,883
Depreciation and amortization	1,086	1,070	3,146	3,109
Total operating expenses	19,693	18,696	58,653	57,238
Operating income	7,339	6,548	22,363	18,741
Interest income	12	14	34	46
Interest expense	(38)	(52)	(158)	(172)
Other, net	(4)	(25)	112	(22)
Total other income (expense)	(30)	(63)	(12)	(148)
Income before income taxes	7,309	6,485	22,351	18,593
Provision for income taxes	(2,580)	(2,346)	(7,558)	(6,910)
Net income	$ 4,729	$ 4,139	$ 14,793	$ 11,683