Segment Information - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 121,307	$ 106,456	$ 391,382	$ 336,480
Adjusted EBITDA	14,832	8,175	61,288	35,596
Software [Member]
Segment Reporting Information [Line Items]
Revenue	109,939	93,980	354,617	296,634
Adjusted EBITDA	14,103	7,071	58,957	32,637
CES [Member]
Segment Reporting Information [Line Items]
Revenue	10,060	10,868	31,005	34,386
Adjusted EBITDA	1,408	1,607	3,630	4,086
All Other [Member]
Segment Reporting Information [Line Items]
Revenue	1,308	1,608	5,760	5,460
Adjusted EBITDA	$ (679)	$ (503)	$ (1,299)	$ (1,127)