Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) attributable to Tutor Perini Corporation	$ 36,819	$ 19,313	$ 72,899	$ (301,573)
Weighted-average common shares outstanding, basic (in shares)	50,787	50,279	50,598	50,201
Effect of dilutive restricted stock units and stock options (in shares)	454	303	406	0
Weighted-average common shares outstanding, diluted (in shares)	51,241	50,582	51,004	50,201
Net (loss) income attributable to Tutor Perini Corporation per common share: Basic (in dollars per share)	$ 0.72	$ 0.38	$ 1.44	$ (6.01)
Net (loss) income attributable to Tutor Perini Corporation per common share: Diluted (in dollars per share)	$ 0.72	$ 0.38	$ 1.43	$ (6.01)
Anti-dilutive securities not included above (in shares)	1,514	1,665	1,977	3,458