Earnings Per Common Share (EPS) (Calculations of the Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Common Share (EPS) [Abstract]
Net income attributable to Tutor Perini Corporation	$ 21,272	$ 23,584	$ 34,031	$ 67,444
Weighted-average common shares outstanding, basic	50,018	49,775	49,927	49,602
Effect of dilutive restricted stock units and stock options	357	812	283	1,166
Weighted-average common shares outstanding, diluted	50,375	50,587	50,210	50,768
Net income attributable to Tutor Perini Corporation per common share: Basic	$ 0.43	$ 0.47	$ 0.68	$ 1.36
Net income attributable to Tutor Perini Corporation per common share: Diluted	$ 0.42	$ 0.47	$ 0.68	$ 1.33
Anti-dilutive securities not included above	2,107	912	2,765	752