Quarterly Results of Operations - unaudited (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total Revenue	$ 59,153	$ 52,276	$ 52,277	$ 50,775	$ 52,928	$ 51,439	$ 54,954	$ 56,370	$ 214,481	$ 215,691	$ 253,484
Costs of sales									71,546	67,632	85,646
Gross profit	37,467	36,395	34,831	34,242	38,215	34,954	35,616	39,274	142,935	148,059	167,838
Sales and marketing	16,092	14,449	15,021	17,168	15,680	13,569	13,581	13,833	62,730	56,663	57,819
Operating costs	43,426	38,411	43,690	43,536	40,256	37,309	37,303	38,449	169,063	153,317	153,649
Operating income (loss)	(5,959)	(2,016)	(8,859)	(9,294)	(2,041)	(2,355)	(1,687)	825	(26,128)	(5,258)	14,189
Provision (benefit) for income taxes	6,847	(762)	(1,143)	(501)	277	95	973	690
Net income	$ (13,773)	$ (975)	$ (6,685)	$ (9,151)	$ (1,756)	$ (1,678)	$ (2,025)	$ 4	$ (30,584)	$ (5,455)	$ 7,864
Net income/(loss) per share:
Basic	$ (0.35)	$ (0.02)	$ (0.17)	$ (0.23)	$ (0.04)	$ (0.04)	$ (0.05)	$ 0.00	$ (0.77)	$ (0.14)	$ 0.20
Diluted	$ (0.35)	$ (0.02)	$ (0.17)	$ (0.23)	$ (0.04)	$ (0.04)	$ (0.05)	$ 0.00	$ (0.77)	$ (0.14)	$ 0.20
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs of sales										$ 4,193	$ 3,684
Gross profit				$ 1,200				$ 1,000		(4,193)	(3,684)
Sales and marketing			$ 1,000				$ 1,100			(4,193)	(3,684)
Operating costs		$ 1,000				$ 1,000				(4,193)	(3,684)
Product and license
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total Revenue									$ 120,358	132,986	183,313
Costs of sales	$ 15,377	9,502	10,565	10,752	$ 9,489	11,071	13,689	11,764	$ 46,196	46,013	67,077
Product and license | Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs of sales		$ 1,000	$ 1,000	$ 1,200	$ 1,000	$ 1,000	$ 1,100	$ 1,000		$ 4,193	$ 3,684