Other Comprehensive Income (Loss) (Schedule Of Changes In AOCI Balances By Component (After-Tax)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period			$ 1,553,856
Other comprehensive income (loss) before reclassifications	$ (1,069)	$ 579	(1,700)	$ 1,268
Amounts reclassified from AOCI	435	202	1,281	1,016
Total other comprehensive income (loss)	(634)	781	(419)	2,284
Balance at the end of the period	1,621,286		1,621,286
Defined Benefit Pension Plan
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(43,104)	(36,979)	(44,087)	(37,826)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from AOCI	492	424	1,475	1,271
Total other comprehensive income (loss)	492	424	1,475	1,271
Balance at the end of the period	(42,612)	(36,555)	(42,612)	(36,555)
Foreign Currency Translation
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(5,126)	(6,563)	(5,322)	(5,371)
Other comprehensive income (loss) before reclassifications	(678)	582	(482)	(610)
Amounts reclassified from AOCI	0	0	0	0
Total other comprehensive income (loss)	(678)	582	(482)	(610)
Balance at the end of the period	(5,804)	(5,981)	(5,804)	(5,981)
Unrealized Gain (Loss) in Fair Value of Investments, Net
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	1,704	2,945	2,668	1,097
Other comprehensive income (loss) before reclassifications	(391)	(3)	(1,218)	1,878
Amounts reclassified from AOCI	(57)	(222)	(194)	(255)
Total other comprehensive income (loss)	(448)	(225)	(1,412)	1,623
Balance at the end of the period	1,256	2,720	1,256	2,720
Accumulated Other Comprehensive Income (Loss)
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(46,526)	(40,597)	(46,741)	(42,100)
Balance at the end of the period	$ (47,160)	$ (39,816)	$ (47,160)	$ (39,816)