Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenue	$ 24,001	$ 22,354	$ 50,031	$ 47,260
Operating expenses:
Direct	10,773	9,498	21,102	19,744
Selling, general and administrative	5,984	6,391	12,349	12,884
Depreciation and amortization	926	931	1,861	1,882
Total operating expenses	17,683	16,820	35,312	34,510
Operating income	6,318	5,534	14,719	12,750
Other income (expense):
Interest income	19	12	36	31
Interest expense	(78)	(101)	(160)	(217)
Other, net	7	18	14	32
Total other expense	(52)	(71)	(110)	(154)
Income before income taxes	6,266	5,463	14,609	12,596
Provision for income taxes	2,215	2,029	5,104	4,692
Net income	$ 4,051	$ 3,434	$ 9,505	$ 7,904
Common Class A [Member]
Basic Earnings Per Share:
Basic earnings per share (in Dollars per share)	$ 0.10	$ 0.08	$ 0.23	$ 0.19
Diluted Earnings Per Share:
Diluted earnings per share (in Dollars per share)	$ 0.10	$ 0.08	$ 0.22	$ 0.19
Dividends Per Share of Common Stock:
Dividends per share (in Dollars per share)				$ 0.05
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in Shares)	20,771	20,672	20,757	20,671
Weighted average shares and share equivalents outstanding, diluted (in Shares)	21,073	21,085	21,098	21,074
Common Class B [Member]
Basic Earnings Per Share:
Basic earnings per share (in Dollars per share)	$ 0.58	$ 0.50	$ 1.37	$ 1.15
Diluted Earnings Per Share:
Diluted earnings per share (in Dollars per share)	$ 0.57	$ 0.49	$ 1.34	$ 1.12
Dividends Per Share of Common Stock:
Dividends per share (in Dollars per share)				$ 0.31
Weighted average shares and share equivalents outstanding:
Weighted average shares and share equivalents outstanding, basic (in Shares)	3,474	3,445	3,472	3,445
Weighted average shares and share equivalents outstanding, diluted (in Shares)	3,539	3,516	3,540	3,513