CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUE	$ 4,140,364	$ 3,073,636	$ 2,856,659
COST OF SERVICES	3,398,756	2,510,429	2,309,676
Gross profit	741,608	563,207	546,983
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	489,344	376,309	357,777
GAIN ON SALE OF ASSETS	(1,585)	(1,540)	(1,445)
Operating income	253,849	188,438	190,651
OTHER INCOME (EXPENSE):
Interest income	46	24	103
Interest expense	(13,352)	(6,196)	(8,385)
Changes in the fair value of contingent earn-out obligations	(4,819)	7,820	9,119
Other	134	188	52
Other income (expense)	(17,991)	1,836	889
INCOME BEFORE INCOME TAXES	235,858	190,274	191,540
PROVISION (BENEFIT) FOR INCOME TAXES	(10,089)	46,926	41,401
NET INCOME	$ 245,947	$ 143,348	$ 150,139
INCOME PER SHARE:
Basic	$ 6.84	$ 3.95	$ 4.11
Diluted	$ 6.82	$ 3.93	$ 4.09
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic	35,932	36,285	36,542
Diluted	36,046	36,450	36,738