Other Comprehensive Income (Loss) (Schedule Of Changes In AOCI Balances By Component (After-Tax)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	$ 1,553,856
Other comprehensive income (loss) before reclassifications	(984)	$ (1,447)
Amounts reclassified from AOCI	369	419
Total other comprehensive income (loss)	(615)	(1,028)
Balance at the end of the period	1,569,625
Defined Benefit Pension Plan
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(44,087)	(37,826)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	492	423
Total other comprehensive income (loss)	492	423
Balance at the end of the period	(43,595)	(37,403)
Foreign Currency Translation
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(5,322)	(5,371)
Other comprehensive income (loss) before reclassifications	76	(1,993)
Amounts reclassified from AOCI	0	0
Total other comprehensive income (loss)	76	(1,993)
Balance at the end of the period	(5,246)	(7,364)
Unrealized Gain (Loss) in Fair Value of Investments, Net
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	2,668	1,097
Other comprehensive income (loss) before reclassifications	(1,060)	546
Amounts reclassified from AOCI	(123)	(4)
Total other comprehensive income (loss)	(1,183)	542
Balance at the end of the period	1,485	1,639
Accumulated Other Comprehensive Income (Loss)
Attributable to Tutor Perini Corporation:
Balance at the beginning of the period	(46,741)	(42,100)
Balance at the end of the period	$ (47,356)	$ (43,128)