CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUE	$ 535,043	$ 465,411	$ 999,984	$ 845,999
COST OF SERVICES	423,860	369,673	799,748	674,307
Gross profit	111,183	95,738	200,236	171,692
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	71,208	66,599	141,231	129,846
GOODWILL IMPAIRMENT				1,105
GAIN ON SALE OF ASSETS	(200)	(126)	(411)	(280)
Operating income	40,175	29,265	59,416	41,021
OTHER INCOME (EXPENSE):
Interest income	14	28	28	39
Interest expense	(736)	(1,041)	(1,449)	(1,431)
Changes in the fair value of contingent earn-out obligations	(94)	(598)	59	(624)
Other	3,985	29	4,023	47
Other income (expense)	3,169	(1,582)	2,661	(1,969)
INCOME BEFORE INCOME TAXES	43,344	27,683	62,077	39,052
PROVISION FOR INCOME TAXES	10,797	9,711	12,871	13,603
NET INCOME	$ 32,547	$ 17,972	$ 49,206	$ 25,449
INCOME PER SHARE:
Basic (in shares)	$ 0.87	$ 0.48	$ 1.32	$ 0.68
Diluted (in shares)	$ 0.87	$ 0.48	$ 1.31	$ 0.67
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic (in shares)	37,220	37,296	37,206	37,272
Diluted (in shares)	37,605	37,705	37,617	37,714
DIVIDENDS PER SHARE (in dollars per share)	$ 0.080	$ 0.075	$ 0.155	$ 0.145