CONDENSED CONSOLIDATED STATEMENTS OF 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
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Revenue	$ 908,902	$ 608,311	$ 2,061,808	$ 1,800,978
Cost of revenue	802,397	537,890	1,839,324	1,591,021
Gross profit	106,505	70,421	222,484	209,957
Selling, general and administrative expenses	51,604	42,321	132,049	126,835
Acquisition and related costs	3,827	238	13,190	1,555
Operating income	51,074	27,862	77,245	81,567
Other income (expense):
Investment income		6,066		6,066
Foreign exchange gain	(69)	167	1,444	299
Other income (expense), net	32	(39)	(751)	(52)
Interest income	932	228	1,544	411
Interest expense	(6,448)	(2,198)	(11,637)	(6,605)
Income before provision for income taxes	45,521	32,086	67,845	81,686
Provision for income taxes	(10,716)	(9,952)	(14,633)	(28,644)
Net income	34,805	22,134	53,212	53,042
Less net income attributable to noncontrolling interests	(2,114)	(1,537)	(8,118)	(3,209)
Net income attributable to Primoris	$ 32,691	$ 20,597	$ 45,094	$ 49,833
Dividends per common share (in dollars per share)	$ 0.060	$ 0.055	$ 0.180	$ 0.170
Earnings per share:
Basic (in dollars per share)	0.64	0.40	0.88	0.97
Diluted (in dollars per share)	$ 0.63	$ 0.40	$ 0.87	$ 0.96
Weighted average common shares outstanding:
Basic (in shares)	51,403	51,441	51,471	51,491
Diluted (in shares)	51,735	51,707	51,760	51,751