Other Comprehensive Income (Loss) (Schedule Of Tax Effects Of The Components Of Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Comprehensive Income (Loss) [Abstract]
Defined benefit pension plan adjustments, Before-Tax Amount	$ 513	$ 456	$ 1,539	$ 1,368
Defined benefit pension plan adjustments, Tax (Expense) Benefit	(148)	(187)	(439)	(562)
Defined benefit pension plan adjustments, Net-of-Tax Amount	365	269	1,100	806
Foreign currency translation adjustments, Before-Tax Amount	519	1,232	(2,034)	2,242
Foreign currency translation adjustments, Tax (Expense) Benefit	(143)	(506)	602	(921)
Foreign currency translation adjustments, Net-of-Tax Amount	376	726	(1,432)	1,321
Unrealized (loss) gain in fair value of investments, Before-Tax Amount	(173)	21	(1,468)	(20)
Unrealized (loss) gain in fair value of investments, Tax (Expense) Benefit	44	(9)	325	8
Unrealized (loss) gain in fair value of investments, Net-of-Tax Amount	(129)	12	(1,143)	(12)
Total other comprehensive income (loss), Before-Tax Amount	859	1,709	(1,963)	3,590
Total other comprehensive income (loss), Tax (Expense) Benefit	(247)	(702)	488	(1,475)
Total other comprehensive income (loss), Net-of-Tax Amount	612	1,007	(1,475)	2,115
Total other comprehensive income (loss) attributable to Tutor Perini Corporation, Before-Tax Amount	859	1,709	(1,963)	3,590
Total other comprehensive income (loss) attributable to Tutor Perini Corporation, Tax (Expense) Benefit	(247)	(702)	488	(1,475)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	$ 612	$ 1,007	$ (1,475)	$ 2,115