Other Comprehensive Income (Loss) (AOCI Reclassifications) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income, net	$ (175)	$ (481)
Income tax expense (benefit)	6,964	5,134
Net income attributable to Tutor Perini Corporation	(16,034)	(17,371)
Defined Benefit Pension Plan | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income, net	683	591
Income tax expense (benefit)	(191)	(168)
Net income attributable to Tutor Perini Corporation	492	423
Unrealized gain in fair value of investment adjustments | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income, net	(156)	(5)
Income tax expense (benefit)	33	1
Net income attributable to Tutor Perini Corporation	$ (123)	$ (4)