Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Significant Accounting Policies [Abstract]

Costs and Estimated Earnings in Excess of Billings

	As of December 31,
(in thousands)	2017		2016
Claims	$	549,849	$	477,425
Unapproved change orders		296,591		207,475
Other unbilled costs and profits		86,318		146,926
Total costs and estimated earnings in excess of billings	$	932,758	$	831,826

Calculations of Basic and Diluted EPS

	Year Ended December 31,
(in thousands, except per common share data)	2017		2016		2015
Net income attributable to Tutor Perini Corporation	$	148,382	$	95,822	$	45,292
Weighted-average common shares outstanding, basic		49,647		49,150		48,981
Effect of dilutive stock options and unvested restricted stock		1,112		714		685
Weighted-average common shares outstanding, diluted		50,759		49,864		49,666
Net income attributable to Tutor Perini Corporation per common share:
Basic	$	2.99	$	1.95	$	0.92
Diluted	$	2.92	$	1.92	$	0.91
Anti-dilutive securities not included above		798		1,132		1,372

Schedule of Cash and Cash Equivalents

	As of December 31,
(in thousands)	2017		2016
Cash and cash equivalents	$	94,713	$	49,539
Joint venture cash and cash equivalents		98,155		96,564
Total cash and cash equivalents	$	192,868	$	146,103

Tax Effects of Componenets of Other Comprehensive Income (Loss)

	Year Ended December 31,
	2017						2016						2015
(in thousands)	Before-Tax Amount		Tax (Expense) Benefit		Net-of-Tax Amount		Before-Tax Amount		Tax Benefit		Net-of-Tax Amount		Before-Tax Amount		Tax Benefit (Expense)		Net-of-Tax Amount
Other comprehensive income (loss):
Defined benefit pension plan adjustments	$	2,416	$	(992)	$	1,424	$	(4,452)	$	1,829	$	(2,623)	$	31	$	1,995	$	2,026
Foreign currency translation adjustment		2,159		(886)		1,273		(439)		178		(261)		(5,897)		2,683		(3,214)
Unrealized (loss) gain in fair value of investments		(4)		2		(2)		(576)		236		(340)		1,123		(357)		766
Unrealized loss in fair value of interest rate swap		—		—		—		(45)		21		(24)		(37)		(88)		(125)
Total other comprehensive income (loss)	$	4,571	$	(1,876)	$	2,695	$	(5,512)	$	2,264	$	(3,248)	$	(4,780)	$	4,233	$	(547)
Total other comprehensive income (loss) attributable to Tutor Perini Corporation	$	4,571	$	(1,876)	$	2,695	$	(5,512)	$	2,264	$	(3,248)	$	(4,780)	$	4,233	$	(547)

Changes in AOCI Balances by Component

(in thousands)	Defined Benefit Pension Plan		Foreign Currency Translation		Unrealized (Loss) Gain in Fair Value of Investments		Unrealized Gain (Loss) in Fair Value of Interest Rate Swap		Accumulated Other Comprehensive Loss
Attributable to Tutor Perini Corporation:
Balance as of December 31, 2014	$	(40,268)	$	(1,389)	$	(110)	$	149	$	(41,618)
Other comprehensive income (loss)		2,026		(3,214)		766		(125)		(547)
Balance as of December 31, 2015	$	(38,242)	$	(4,603)	$	656	$	24	$	(42,165)
Other comprehensive loss before reclassifications		(3,722)		(261)		(340)		(24)		(4,347)
Amounts reclassified from AOCI		1,099		—		—		—		1,099
Balance as of December 31, 2016	$	(40,865)	$	(4,864)	$	316	$	—	$	(45,413)
Other comprehensive income (loss) before reclassifications		306		1,273		(2)		—		1,577
Amounts reclassified from AOCI		1,118		—		—		—		1,118
Balance as of December 31, 2017	$	(39,441)	$	(3,591)	$	314	$	—	$	(42,718)

Schedule Of Items Reclassified Out Of AOCI And The Corresponding Location And Impact On The Consolidated Statements Of Income

	Location in Consolidated	Year Ended December 31,
(in thousands)	Statements of Income	2017		2016		2015
Defined benefit pension plan adjustments	Various accounts(a)	$	1,897	$	1,745	$	—
Income tax benefit	Income tax benefit (provision)		(779)		(646)		—
Net of tax		$	1,118	$	1,099	$	—

(a)Defined benefit pension plan adjustments were reclassified to cost of operations and general and administrative expenses.