CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
REVENUE	$ 650,302	$ 535,043	$ 1,188,775	$ 999,984
COST OF SERVICES	530,286	423,860	962,094	799,748
Gross profit	120,016	111,183	226,681	200,236
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	84,506	71,208	163,411	141,231
GAIN ON SALE OF ASSETS	(192)	(200)	(411)	(411)
Operating income	35,702	40,175	63,681	59,416
OTHER INCOME (EXPENSE):
Interest income	67	14	92	28
Interest expense	(3,050)	(736)	(4,112)	(1,449)
Changes in the fair value of contingent earn-out obligations	(1,762)	(94)	(1,920)	59
Other	149	3,985	164	4,023
Other income (expense)	(4,596)	3,169	(5,776)	2,661
INCOME BEFORE INCOME TAXES	31,106	43,344	57,905	62,077
PROVISION FOR INCOME TAXES	6,933	10,797	13,866	12,871
NET INCOME	$ 24,173	$ 32,547	$ 44,039	$ 49,206
INCOME PER SHARE:
Basic (in shares)	$ 0.65	$ 0.87	$ 1.19	$ 1.32
Diluted (in shares)	$ 0.65	$ 0.87	$ 1.18	$ 1.31
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic (in shares)	36,943	37,220	36,933	37,206
Diluted (in shares)	37,223	37,605	37,228	37,617
DIVIDENDS PER SHARE (in dollars per share)	$ 0.100	$ 0.080	$ 0.195	$ 0.155