Other Comprehensive Income (Loss) (AOCI Reclassifications) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	$ 464	$ 8,048	$ (1,142)	$ 8,364
Income tax expense (benefit)	8,694	37	26,293	14,747
Net income attributable to Tutor Perini Corporation	(15,394)	(36,819)	(62,593)	(72,899)
Defined Benefit Pension Plan | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	683	592	2,049	1,775
Income tax expense (benefit)	(191)	(168)	(574)	(504)
Net income attributable to Tutor Perini Corporation	492	424	1,475	1,271
Unrealized gain in fair value of investment adjustments | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	(73)	(281)	(246)	(323)
Income tax expense (benefit)	16	59	52	68
Net income attributable to Tutor Perini Corporation	$ (57)	$ (222)	$ (194)	$ (255)