Summary of Significant Accounting Policies (Calculations of Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Net income (loss) attributable to Tutor Perini Corporation	$ (86,117)	$ 19,313	$ (320,530)	$ (356)	$ 49,405	$ 21,272	$ 24,883	$ (12,124)	$ (387,690)	$ 83,436	$ 148,382
Weighted-average common shares outstanding, basic									50,220	49,952	49,647
Effect of dilutive restricted stock units and stock options										349	1,112
Weighted-average common shares outstanding, diluted									50,220	50,301	50,759
Net income (loss) attributable to Tutor Perini Corporation per common share: Basic	$ (1.71)	$ 0.38	$ (6.38)	$ (0.01)	$ 0.99	$ 0.43	$ 0.50	$ (0.24)	$ (7.72)	$ 1.67	$ 2.99
Net income (loss) attributable to Tutor Perini Corporation per common share: Diluted	$ (1.71)	$ 0.38	$ (6.38)	$ (0.01)	$ 0.98	$ 0.42	$ 0.49	$ (0.24)	$ (7.72)	$ 1.66	$ 2.92
Anti-dilutive securities not included above									3,640	2,670	798