Other Comprehensive Income (Loss) (Schedule Of Components Of Other Comprehensive Income (Loss) And Related Tax Effects) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Comprehensive Income (Loss) [Abstract]
Defined benefit pension plan adjustments, Before-Tax Amount		$ 592	$ 464	$ 1,183	$ 926
Defined benefit pension plan adjustments, Tax (Expense) Benefit		(168)	(133)	(336)	(265)
Defined benefit pension plan adjustments, Net-of-Tax Amount		424	331	847	661
Foreign currency translation adjustment, Before-Tax Amount		1,973	1,072	(2,954)	1,551
Foreign currency translation adjustment, Tax (Expense) Benefit		(318)	(262)	596	(393)
Foreign currency translation adjustment, Net-of-Tax Amount		1,655	810	(2,358)	1,158
Unrealized gain in fair value of investments, Before-Tax Amount		1,602	867	2,359	1,725
Unrealized gain in fair value of investments, Tax (Expense) Benefit		(296)	(181)	(511)	(366)
Unrealized gain in fair value of investments, Net-of-Tax Amount		1,306	686	1,848	1,359
Total other comprehensive income, Before-Tax Amount		4,167	2,403	588	4,202
Total other comprehensive income, Tax Benefit (Expense)		(782)	(576)	(251)	(1,024)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX		3,385	1,827	337	3,178
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Before-Tax Amount	[1]	854	157	(1,166)	259
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Tax (Expense) Benefit	[1]	0	0	0	0
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Net-of-Tax Amount	[1]	854	157	(1,166)	259
Total other comprehensive income attributable to Tutor Perini Corporation, Before-Tax Amount		3,313	2,246	1,754	3,943
Total other comprehensive income attributable to Tutor Perini Corporation, Tax (Expense) Benefit		(782)	(576)	(251)	(1,024)
Total other comprehensive income (loss), net of tax		$ 2,531	$ 1,670	$ 1,503	$ 2,919

[1] The only component of other comprehensive income (loss) attributable to noncontrolling interests is foreign currency translation.