CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
OPERATING ACTIVITIES:
Net loss	$ (25,325)	$ (57,949)	$ (23,557)
Adjustments to reconcile net loss to net cash provided by operating activities:
Provision for bad debt	1,135	4,532	1,246
DEPRECIATION AND AMORTIZATION	44,810	37,274	27,705
Amortization of right-of-use asset	8,151
Stock-based compensation expense	10,321	4,849	4,345
Fair value changes in financial instruments	2,195	20,319	11,160
Fair value changes in business acquisitions contingent consideration	24,372	12,942	1,392
Deferred income taxes	1,709	851	(3,121)
Amortization of deferred financing costs	404	1,810	560
Debt extinguishment costs	4,052
Other	(599)	278	(363)
Changes in operating assets and liabilities—net of acquisitions:
Accounts receivable and contract assets	(36,164)	(19,202)	(6,588)
Prepaid expenses and other current assets	(886)	(956)	(2,461)
Accounts payable and other accrued liabilities	23,996	601	6,085
Accrued payroll and benefits	3,244	6,072	2,248
Payment of contingent consideration and other assumed purchase price obligations	(15,628)	(6,390)
Change in operating leases	(7,944)
Other assets	(262)	(3,181)	(1,609)
Net cash provided by operating activities	37,581	1,850	17,042
INVESTING ACTIVITIES:
Proceeds from property insurance	413		360
Purchases of property and equipment	(6,885)	(7,206)	(4,692)
Proceeds received from the sale of property and equipment	597	20	260
Proprietary software development and other software costs	(699)	(570)	(21)
Payment of assumed purchase price obligations	(9,336)		(1,520)
Proceeds from net working capital adjustment related to acquisitions		1,939
Cash paid for acquisitions—net of cash acquired	(55,731)	(173,923)	(81,370)
Net cash used in investing activities	(71,641)	(179,740)	(86,983)
FINANCING ACTIVITIES:
Proceeds from line of credit	109,000	104,390	146,338
Payments on line of credit	(109,000)	(201,980)	(68,747)
Proceeds from term loans	175,000	175,000
Repayment of term loans	(173,905)	(49,844)	(1,250)
Payment of contingent consideration and other assumed purchase price obligations	(9,865)	(6,004)	(1,113)
Repayment of finance leases	(2,711)	(2,848)	(1,972)
Proceeds from issuance of common stock in public offerings, net of issuance costs	169,783	161,288
Payments of deferred offering costs	(446)	(4,164)
Prepayment premium on credit facility		(351)	(435)
Debt issuance cost	(2,590)	(4,866)
Proceeds from issuance of common stock for exercised stock options	7,237	408	1,509
Issuance of series A-1 and series A-2 preferred stock and warrant, net of issuance costs		173,664
Redemption of the series A-1 preferred stock		(131,821)
Dividend payment to the series A-2 shareholders	(16,400)	(6,970)
Collection of notes receivable			122
Net cash provided by financing activities	146,103	205,902	74,452
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	112,043	28,012	4,511
Foreign exchange impact on cash balance	(183)	(15)	(116)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH:
Beginning of year	34,881	6,884	2,489
End of year	146,741	34,881	6,884
SUPPLEMENTAL DISCLOSURES OF CASH FLOWS INFORMATION:
Cash paid for interest	5,012	11,947	5,891
Cash paid for income tax	412	171	1,205
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Preferred stock deemed dividend—net of return from holders		24,341
Redemption of preferred stock in common shares		26,801
Accrued purchases of property and equipment	790	432	975
Property and equipment purchased under finance leases	1,766	2,113	4,347
Accretion of the redeemable series A-1 preferred stock to redeemable value		17,601	19,616
Common stock issued to acquire new businesses	8,320	25,000	4,047
Acquisitions unpaid contingent consideration	35,800	$ 54,467	5,402
Acquisitions contingent consideration paid in shares	26,084
Offering costs included in accounts payable and other accrued liabilities	$ 183		$ 1,240