Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income tax provision (benefit)	$ 14,278	$ 22,886	$ 25,572	$ 53,307
Effective tax rate (as a percent)	42.00%	39.00%	41.10%	39.90%
Unrecognized tax benefits, including related interest and penalties			$ 7,600
Unrecognized tax benefits that would impact the effective tax rate	$ 6,700		6,700
Unrecognized tax benefits interest that would impact the effective tax rate	900		900
Tutor Perini Corporation [Member]
Income tax provision (benefit)	$ 10,782	$ (1,489)	$ 9,696	$ (3,229)