UNAUDITED QUARTERLY OPERATING RESULTS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 141,156	$ 134,590	$ 93,589	$ 91,119	$ 87,074	$ 90,385	$ 91,566	$ 85,180	$ 460,454	$ 354,205	$ 344,900
Operating expenses
Selling & administrative	9,354	8,817	8,316	8,064	8,727	8,153	8,356	9,964	34,551	35,200	32,747
Enterprise technology & product support	7,694	7,342	7,201	7,254	6,917	6,743	6,745	6,445
Depreciation & amortization	3,762	3,528	3,473	3,482	3,535	3,524	3,130	2,421	14,245	12,610	9,117
Total operating expenses	117,232	104,784	75,210	75,795	75,330	72,414	73,837	70,205	373,021	291,786	269,840
Total operating expenses	23,924	29,806	18,379	15,324	11,744	17,971	17,729	14,975	87,433	62,419	75,060
Interest income	0	0	0	389	604	729	577	604	389	2,514	616
Income before income taxes	23,924	29,806	18,379	15,713	12,348	18,700	18,306	15,579	87,822	64,933	75,676
Income tax provision	6,080	4,715	4,583	3,850	2,390	4,190	3,846	4,077	19,228	14,503	17,407
Net income	$ 17,844	$ 25,091	$ 13,796	$ 11,863	$ 9,958	$ 14,510	$ 14,460	$ 11,502	$ 68,594	$ 50,430	$ 58,269
Basic net income per share (in usd per share)	$ 0.26	$ 0.37	$ 0.20	$ 0.18	$ 0.15	$ 0.21	$ 0.21	$ 0.17	$ 1.01	$ 0.75	$ 0.87
Diluted net income per share (in usd per share)	$ 0.26	$ 0.37	$ 0.20	$ 0.18	$ 0.15	$ 0.21	$ 0.21	$ 0.17	$ 1.01	$ 0.75	$ 0.87
Weighted average shares outstanding
Basic (in shares)	67,030	67,025	66,999	66,987	66,967	66,960	66,940	66,670	67,010	66,884	66,499
Diluted (in shares)	67,166	67,025	66,999	66,987	66,967	66,960	66,940	66,670	67,117	66,884	66,560
State enterprise revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 88,030	$ 91,475	$ 77,804	$ 74,411	$ 72,300	$ 73,257	$ 74,871	$ 69,853	$ 331,720	$ 290,281	$ 312,492
Operating expenses
Cost of Revenue	53,947	53,807	45,876	46,271	44,610	43,821	45,081	41,978	199,901	175,490	187,321
Software & services revenues
Disaggregation of Revenue [Line Items]
Revenues	53,126	43,115	15,785	16,708	14,774	17,128	16,695	15,327	128,734	63,924	32,408
Operating expenses
Cost of Revenue	$ 42,475	$ 31,290	$ 10,344	$ 10,724	$ 11,541	$ 10,173	$ 10,525	$ 9,397	$ 94,833	$ 41,636	$ 16,711