CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Revenue from Contract with Customer, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]	Service [Member]
Revenue from services	$ 636,098	$ 374,905	$ 2,178,391	$ 1,035,973
Operating expenses:
Direct operating expenses	492,553	291,111	1,689,647	808,124
Selling, general and administrative expenses	80,216	52,847	243,038	149,518
Bad debt expense	1,101	1,441	6,662	2,411
Depreciation and amortization	3,214	2,680	9,414	7,132
Acquisition and integration-related costs	490	61	530	985
Restructuring costs	2,493	318	1,859	2,391
Impairment charges	3,856	0	5,597	2,070
Total operating expenses	583,923	348,458	1,956,747	972,631
Income from operations	52,175	26,447	221,644	63,342
Other expenses (income):
Interest expense	3,498	2,182	10,876	4,049
Loss on early extinguishment of debt	0	0	1,912	0
Other income, net	(27)	(375)	(1,119)	(616)
Income before income taxes	48,704	24,640	209,975	59,909
Income tax expense	13,911	1,207	60,305	5,480
Net income attributable to common stockholders	34,793	23,433	149,670	54,429
Other comprehensive income:
Unrealized foreign currency translation loss, net of tax	(38)	(2)	(80)	(32)
Comprehensive income	$ 34,755	$ 23,431	$ 149,590	$ 54,397
Net income per share attributable to common stockholders - Basic (in dollars per share)	$ 0.94	$ 0.63	$ 4.02	$ 1.49
Net income per share attributable to common stockholders - Diluted (in dollars per share)	$ 0.93	$ 0.62	$ 3.97	$ 1.46
Weighted average common shares outstanding:
Basic (shares)	37,101	36,963	37,200	36,593
Diluted (shares)	37,492	37,582	37,741	37,276