CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUE	$ 538,473	$ 464,941
COST OF SERVICES	431,808	375,888
Gross profit	106,665	89,053
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	78,905	70,023
GAIN ON SALE OF ASSETS	(219)	(211)
Operating income	27,979	19,241
OTHER INCOME (EXPENSE):
Interest income	25	14
Interest expense	(1,062)	(713)
Changes in the fair value of contingent earn-out obligations	(158)	153
Other	15	38
Other income (expense)	(1,180)	(508)
INCOME BEFORE INCOME TAXES	26,799	18,733
PROVISION FOR INCOME TAXES	6,933	2,074
NET INCOME	$ 19,866	$ 16,659
INCOME PER SHARE:
Basic (in shares)	$ 0.54	$ 0.45
Diluted (in shares)	$ 0.53	$ 0.44
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic (in shares)	36,923	37,192
Diluted (in shares)	37,234	37,628
DIVIDENDS PER SHARE (in dollars per share)	$ 0.095	$ 0.075