UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
REVENUES	$ 132,578	$ 84,705	$ 402,619	$ 219,502
COST OF REVENUES (exclusive of depreciation and amortization shown below)	85,242	51,828	272,662	142,115
SELLING, GENERAL AND ADMINISTRATIVE EXPENSE	30,499	24,442	82,865	64,810
FAIR VALUE CHANGES IN BUSINESS ACQUISITIONS CONTINGENT CONSIDERATION		13,404	24,035	17,387
DEPRECIATION AND AMORTIZATION	11,471	9,740	33,145	27,084
INCOME (LOSS) FROM OPERATIONS	5,366	(14,709)	(10,088)	(31,894)
OTHER EXPENSE
Other expense	(516)	(9,637)	(1,909)	(17,534)
Interest expense—net	(1,722)	(3,043)	(11,208)	(10,896)
Total other expenses—net	(2,238)	(12,680)	(13,117)	(28,430)
INCOME (LOSS) BEFORE EXPENSE (BENEFIT) FROM INCOME TAXES	3,128	(27,389)	(23,205)	(60,324)
INCOME TAX EXPENSE (BENEFIT)	902	3,348	648	(1,563)
NET INCOME (LOSS)	2,226	(30,737)	(23,853)	(58,761)
EQUITY ADJUSTMENT FROM FOREIGN CURRENCY TRANSLATION	(74)	80	(17)	27
COMPREHENSIVE INCOME (LOSS)	2,152	(30,657)	(23,870)	(58,734)
ACCRETION OF REDEEMABLE SERIES A-1 PREFERRED STOCK		(6,542)		(17,601)
REDEEMABLE SERIES A-1 PREFERRED STOCK DEEMED DIVIDEND		(24,341)		(24,341)
CONVERTIBLE AND REDEEMABLE SERIES A-2 PREFERRED STOCK DIVIDEND	(4,100)	(2,870)	(12,300)	(2,870)
NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ (1,874)	$ (64,490)	$ (36,153)	$ (103,573)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING— BASIC AND DILUTED	26,220	21,554	25,798	13,669
NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS— BASIC AND DILUTED	$ (0.07)	$ (2.99)	$ (1.40)	$ (7.58)