CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
NET INCOME	$ 25,436	$ 25,300	$ 42,390	$ 71,697
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Defined benefit pension plan adjustments	365	269	1,100	806
Foreign currency translation adjustments	376	726	(1,432)	1,321
Unrealized gain (loss) in fair value of investments	(129)	12	(1,143)	(12)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	612	1,007	(1,475)	2,115
COMPREHENSIVE INCOME	26,048	26,307	40,915	73,812
LESS: COMPREHENSIVE INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	4,164	1,716	8,359	4,253
COMPREHENSIVE INCOME ATTRIBUTABLE TO TUTOR PERINI CORPORATION	$ 21,884	$ 24,591	$ 32,556	$ 69,559