Business Segments (Narrative) (Details) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($) $ / shares	Dec. 31, 2015 USD ($) segment $ / shares	Dec. 31, 2014 USD ($) item $ / shares	Dec. 31, 2013 USD ($) $ / shares
Segment Reporting Information [Line Items]
Number of basic segments | segment									3
Income from construction operations	$ 15,474	$ 38,974	$ 30,881	$ 20,084	$ 64,396	$ 70,354	$ 65,443	$ 41,497	$ 105,413	$ 241,690	$ 203,822
DILUTED EARNINGS PER COMMON SHARE | $ / shares	$ 0.18	$ 0.40	$ 0.24	$ 0.10	$ 0.56	$ 0.73	$ 0.58	$ 0.33	$ 0.91	$ 2.20	$ 1.80
Tutor Perini Corporation [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ 68,595	$ 70,574	$ 12,258
Building [Member]
Segment Reporting Information [Line Items]
Number of projects | item										1
Income from construction operations									(1,240)	$ 24,697	24,579
Building [Member] | Unfavorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ (24,300)
DILUTED EARNINGS PER COMMON SHARE | $ / shares									$ (0.28)
Building [Member] | Favorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations										$ 11,400	$ 13,800
DILUTED EARNINGS PER COMMON SHARE | $ / shares										$ 0.14	$ 0.18
Civil [Member]
Segment Reporting Information [Line Items]
Number of projects | item										2
Income from construction operations									$ 145,213	$ 220,554	$ 177,667
Civil [Member] | Unfavorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations										$ (9,400)
DILUTED EARNINGS PER COMMON SHARE | $ / shares										$ (0.11)
Civil [Member] | Favorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ 13,700	$ 25,900
DILUTED EARNINGS PER COMMON SHARE | $ / shares									$ 0.16	$ 0.30
Specialty Contractors [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ 15,682	$ 50,998	$ 49,008
Five Star Electric [Member] | Unfavorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ (45,600)
DILUTED EARNINGS PER COMMON SHARE | $ / shares									$ (0.53)
Brightwater Matter [Member] | Unfavorable Adjustments [Member]
Segment Reporting Information [Line Items]
Income from construction operations									$ (23,900)
DILUTED EARNINGS PER COMMON SHARE | $ / shares									$ (0.28)