CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues	$ 906,449	$ 667,048	$ 2,470,131	$ 1,946,889
Cost of services	636,277	448,733	1,718,376	1,317,493
Gross profit	270,172	218,315	751,755	629,396
Selling, general and administrative expenses	177,335	149,197	521,395	440,446
Amortization of intangible assets	18,540	8,248	44,689	25,011
Operating income	74,297	60,870	185,671	163,939
Interest expense	(14,606)	(7,099)	(41,724)	(21,667)
Income before income taxes	59,691	53,771	143,947	142,272
Provision for income taxes	10,474	18,892	31,889	51,775
Income from continuing operations	49,217	34,879	112,058	90,497
Loss from discontinued operations, net of income taxes	(45)	(23)	(233)	(153)
Net income	$ 49,172	$ 34,856	$ 111,825	$ 90,344
Earnings per share:
Basic	$ 0.94	$ 0.66	$ 2.14	$ 1.72
Diluted	$ 0.93	$ 0.66	$ 2.11	$ 1.70
Number of shares and share equivalents used to calculate earnings per share:
Basic	52,362	52,500	52,282	52,660
Diluted	53,034	53,173	52,990	53,319
Reconciliation of net income to comprehensive income:
Net income	$ 49,172	$ 34,856	$ 111,825	$ 90,344
Foreign currency translation adjustment	(268)	1,783	(1,428)	5,628
Comprehensive income	$ 48,904	$ 36,639	$ 110,397	$ 95,972