Other Comprehensive Income (Loss) (Schedule Of Components Of Other Comprehensive Income (Loss) And Related Tax Effects) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Defined benefit pension plan adjustments, Before-Tax Amount	$ 592	$ 464	$ 1,775	$ 1,390
Defined benefit pension plan adjustments, Tax (Expense) Benefit	(168)	(133)	(504)	(398)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Net-of-Tax, Total	(424)	(331)	(1,271)	(992)
Foreign currency translation adjustment, Before-Tax Amount	1,333	(590)	(1,621)	961
Foreign currency translation adjustment, Tax (Expense) Benefit	(231)	140	365	(253)
Foreign currency translation adjustment, Net-of-Tax Amount	1,102	(450)	(1,256)	708
Unrealized gain (loss) in fair value of investments, Before-Tax Amount	(281)	328	2,078	2,053
Unrealized gain in fair value of investments, Tax (Expense) Benefit	56	(72)	(455)	(438)
Unrealized gain in fair value of investments, Net-of-Tax Amount	(225)	256	1,623	1,615
Total other comprehensive income, Before-Tax Amount	1,644	202	2,232	4,404
Total other comprehensive income, Tax Benefit (Expense)	(343)	(65)	(594)	(1,089)
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAX	1,301	137	1,638	3,315
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Before-Tax Amount	520	(99)	(646)	160
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Tax (Expense) Benefit	0	0	0	0
Less: Other comprehensive income (loss) attributable to noncontrolling interests, Net-of-Tax Amount	520	(99)	(646)	160
Total other comprehensive income attributable to Tutor Perini Corporation, Before-Tax Amount	1,124	301	2,878	4,244
Total other comprehensive income attributable to Tutor Perini Corporation, Tax (Expense) Benefit	(343)	(65)	(594)	(1,089)
Total other comprehensive income (loss)	$ 781	$ 236	$ 2,284	$ 3,155