Other Comprehensive Income (Loss) (Schedule Of Tax Effects Of The Components Of Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Comprehensive Income (Loss) [Abstract]
Defined benefit pension plan adjustments, Before-Tax Amount	$ 494	$ 456	$ 1,026	$ 912
Defined benefit pension plan adjustments, Tax (Expense) Benefit	(140)	(187)	(291)	(375)
Defined benefit pension plan adjustments, Net-of-Tax Amount	354	269	735	537
Foreign currency translation adjustments, Before-Tax Amount	(914)	1,101	(2,553)	1,009
Foreign currency translation adjustments, Tax (Expense) Benefit	280	(452)	745	(414)
Foreign currency translation adjustments, Net-of-Tax Amount	(634)	649	(1,808)	595
Unrealized (loss) gain in fair value of investments, Before-Tax Amount	(1,176)	(6)	(1,295)	(42)
Unrealized (loss) gain in fair value of investments, Tax (Expense) Benefit	247	3	281	18
Unrealized (loss) gain in fair value of investments, Net-of-Tax Amount	(929)	(3)	(1,014)	(24)
Total other comprehensive income (loss), Before-Tax Amount	(1,596)	1,551	(2,822)	1,879
Total other comprehensive income (loss), Tax (Expense) Benefit	387	(636)	735	(771)
Total other comprehensive income (loss), Net-of-Tax Amount	(1,209)	915	(2,087)	1,108
Total other comprehensive income (loss) attributable to Tutor Perini Corporation, Before-Tax Amount	(1,596)	1,551	(2,822)	1,879
Total other comprehensive income (loss) attributable to Tutor Perini Corporation, Tax (Expense) Benefit	387	(636)	735	(771)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	$ (1,209)	$ 915	$ (2,087)	$ 1,108