Quarterly Results of Operations (Unaudited) - Schedule of Selected Unaudited Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 108,741	$ 84,705	$ 73,766	$ 61,031	$ 67,876	$ 57,623	$ 57,401	$ 50,954	$ 328,243	$ 233,854	$ 188,805
Cost of revenues	73,377	51,828	45,889	44,398	47,735	39,804	39,349	37,095	215,492	163,983	134,734
Selling, general and administrative expense	20,736	18,064	19,318	20,520	13,751	12,636	12,129	10,593	78,638	49,109	40,953
Initial public offering expense		6,378		530	504	20	73	13	6,908	610
Fair value changes in business acquisitions contingent consideration	(4,445)	13,404	3,983		2,062	256	(926)		12,942	1,392	(158)
Depreciation and amortization expense	10,190	9,740	9,784	7,560	7,443	7,412	6,401	6,449	37,274	27,705	23,915
INCOME (LOSS) FROM OPERATIONS	8,883	(14,709)	(5,208)	(11,977)	(3,619)	(2,505)	375	(3,196)	(23,011)	(8,945)	(10,639)
OTHER EXPENSE:
Other (expense) income	(2,734)	(9,637)	21,933	(29,830)	(7,339)	(2,460)	(1,228)	49	(20,268)	(10,978)	265
Interest expense—net	(2,923)	(3,043)	(5,260)	(2,593)	(2,165)	(2,130)	(1,181)	(1,279)	(13,819)	(6,755)	(11,085)
LOSS BEFORE BENEFIT FROM INCOME TAXES	3,226	(27,389)	11,465	(44,400)	(13,123)	(7,095)	(2,034)	(4,426)	(57,098)	(26,678)	(21,459)
Income tax expense (benefit)	2,414	3,348	(1,759)	(3,152)	(1,813)	(412)	(1,712)	816	851	(3,121)	(4,968)
NET INCOME (LOSS)	$ 812	$ (30,737)	$ 13,224	$ (41,248)	$ (11,310)	$ (6,683)	$ (322)	$ (5,242)	$ (57,949)	$ (23,557)	$ (16,491)
Net (loss) income per share attributable to common stockholders—Basic	$ (0.13)	$ (2.99)	$ 0.71	$ (5.24)	$ (1.89)	$ (1.34)	$ (0.59)	$ (1.13)
Net (loss) income per share attributable to common stockholders—Diluted	$ (0.13)	$ (2.99)	$ 0.40	$ (5.24)	$ (1.89)	$ (1.34)	$ (0.59)	$ (1.13)