Quarterly Operating Results (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues:
Portal revenues	$ 54,433,040	$ 50,197,700	$ 49,042,468	$ 45,711,804	$ 42,288,106	$ 43,850,010	$ 43,783,252	$ 40,355,066	$ 199,385,012	$ 170,276,434	$ 155,175,664
Software & services revenues	2,778,391	3,008,474	2,939,332	3,031,317	2,764,733	2,838,915	2,640,677	2,378,412	11,757,514	10,622,737	6,358,195
Total revenues	57,211,431	53,206,174	51,981,800	48,743,121	45,052,839	46,688,925	46,423,929	42,733,478	211,142,526	180,899,171	161,533,859
Operating expenses:
Cost of portal revenues, exclusive of depreciation & amortization	33,443,979	31,794,232	30,549,948	28,750,896	25,824,503	27,122,489	26,362,294	25,420,650	124,539,055	104,729,936	95,552,116
Cost of software & services revenues, exclusive of depreciation & amortization	996,262	1,079,460	1,008,078	957,423	962,221	1,062,767	1,008,960	996,969	4,041,223	4,030,917	3,980,365
Selling & administrative	8,315,285	8,218,715	8,382,643	7,935,303	7,350,510	6,275,587	8,419,671	6,685,990	32,851,946	28,731,758	27,926,440
Amortization of acquisition-related intangible assets		52,054	80,769	80,769	80,769	80,769	80,769	80,769	213,592	323,076	323,076
Depreciation & amortization	2,069,118	1,605,553	1,319,701	1,310,568	1,214,324	1,167,347	1,109,318	1,084,423	6,304,940	4,575,412	4,353,748
Total operating expenses	44,824,644	42,750,014	41,341,139	39,034,959	35,432,327	35,708,959	36,981,012	34,268,801	167,950,756	142,391,099	132,135,745
Operating income	12,386,787	10,456,160	10,640,661	9,708,162	9,620,512	10,979,966	9,442,917	8,464,677	43,191,770	38,508,072	29,398,114
Other income (expense), net	(15,321)			(890)	(28,831)	(9,727)	615	3,123	(16,211)	(34,820)	(9,557)
Income before income taxes	12,371,466	10,456,160	10,640,661	9,707,272	9,591,681	10,970,239	9,443,532	8,467,800	43,175,559	38,473,252	29,388,557
Income tax provision	3,748,853	4,461,320	4,546,917	4,079,721	4,068,644	4,139,018	3,910,303	3,412,805	16,836,811	15,530,770	11,025,510
Net income	$ 8,622,613	$ 5,994,840	$ 6,093,744	$ 5,627,551	$ 5,523,037	$ 6,831,221	$ 5,533,229	$ 5,054,995	$ 26,338,748	$ 22,942,482	$ 18,363,047
Basic net income per share	$ 0.13	$ 0.09	$ 0.09	$ 0.09	$ 0.08	$ 0.11	$ 0.09	$ 0.08	$ 0.40	$ 0.35	$ 0.28
Diluted net income per share	$ 0.13	$ 0.09	$ 0.09	$ 0.09	$ 0.08	$ 0.11	$ 0.09	$ 0.08	$ 0.40	$ 0.35	$ 0.28
Weighted average shares outstanding:
Basic	64,627,150	64,585,659	64,488,837	64,296,996	64,176,446	64,120,253	63,997,854	63,771,121	64,500,244	64,017,813	63,511,383
Diluted	64,696,246	64,603,817	64,488,837	64,296,996	64,324,735	64,199,973	64,060,660	63,831,274	64,564,664	64,156,669	63,609,080