Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue	$ 92,590	$ 86,421	$ 75,767
Operating expenses:
Direct	38,844	35,461	28,667
Selling, general and administrative	25,208	23,542	23,300
Depreciation and amortization	3,732	4,699	5,065
Total operating expenses	67,784	63,702	57,032
Operating income	24,806	22,719	18,735
Other income (expense):
Interest income	63	32	13
Interest expense	(397)	(541)	(629)
Other, net	16	(3)	41
Total other expense	(318)	(512)	(575)
Income before income taxes	24,488	22,207	18,160
Provision for income taxes	9,004	7,139	6,596
Net income	$ 15,484	$ 15,068	$ 11,564
Common Class A [Member]
Basic earnings per share:
Diluted earnings per share (in Dollars per share)	$ 0.37	$ 0.37	$ 0.29
Basic earnings per share (in Dollars per share)	$ 0.37	$ 0.36	$ 0.28
Weighted average shares and share equivalents outstanding
Weighted average shares and share equivalents outstanding, basic (in Shares)	20,677	20,325	20,016
Weighted average shares and share equivalents outstanding, diluted (in Shares)	21,099	20,854	20,526
Common Class B [Member]
Basic earnings per share:
Diluted earnings per share (in Dollars per share)	$ 2.20	$ 2.17	$ 1.69
Basic earnings per share (in Dollars per share)	$ 2.25	$ 2.22	$ 1.73
Weighted average shares and share equivalents outstanding
Weighted average shares and share equivalents outstanding, basic (in Shares)	3,447	3,388	3,336
Weighted average shares and share equivalents outstanding, diluted (in Shares)	3,514	3,476	3,421