CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 78,649	$ 87,028	$ 92,498	$ 86,725	$ 83,472	$ 84,533	$ 85,326	$ 83,177	$ 344,900	$ 336,508	$ 317,915
Operating expenses:
Selling & administrative	14,848	14,690	14,003	13,150	13,898	12,091	13,131	11,660	56,691	50,780	47,063
Depreciation & amortization	2,466	2,441	2,145	2,065	1,818	1,810	1,688	1,613	9,117	6,929	6,749
Total operating expenses	66,080	67,581	70,094	66,085	66,049	64,447	65,607	62,068	269,840	258,171	240,057
Operating income (loss)	12,569	19,447	22,404	20,640	17,423	20,086	19,719	21,109	75,060	78,337	77,858
Other income:
Interest income	406	153	57	0					616	0	0
Income before income taxes	12,975	19,600	22,461	20,640					75,676	78,337	77,858
Income tax provision	3,127	3,698	5,450	5,132	6,583	6,066	6,950	7,124	17,407	26,723	22,025
Net income	$ 9,848	$ 15,902	$ 17,011	$ 15,508	$ 10,840	$ 14,020	$ 12,769	$ 13,985	$ 58,269	$ 51,614	$ 55,833
Basic net income per share (in usd per share)	$ 0.15	$ 0.24	$ 0.25	$ 0.23	$ 0.16	$ 0.21	$ 0.19	$ 0.21	$ 0.87	$ 0.77	$ 0.84
Diluted net income per share (in usd per share)	$ 0.15	$ 0.24	$ 0.25	$ 0.23	$ 0.16	$ 0.21	$ 0.19	$ 0.21	$ 0.87	$ 0.77	$ 0.84
Weighted average shares outstanding:
Basic (in shares)	66,569	66,562	66,541	66,323	66,270	66,267	66,248	66,046	66,499	66,209	65,913
Diluted (in shares)	66,641	66,598	66,561	66,323	66,334	66,267	66,248	66,046	66,560	66,266	65,966
Portal
Revenues	$ 72,354	$ 80,884	$ 86,555	$ 80,791	$ 78,345	$ 76,434	$ 79,374	$ 77,198	$ 320,584	$ 311,351	$ 296,998
Operating expenses:
Cost of portal revenues, exclusive of depreciation & amortization	46,412	48,224	51,711	48,642	48,154	47,377	49,009	47,032	194,989	191,572	180,287
Software & services
Revenues	6,295	6,144	5,943	5,934	5,127	8,099	5,952	5,979	24,316	25,157	20,917
Operating expenses:
Cost of portal revenues, exclusive of depreciation & amortization	$ 2,354	$ 2,226	$ 2,235	$ 2,228	$ 2,179	$ 3,169	$ 1,779	$ 1,763	$ 9,043	$ 8,890	$ 5,958