Contingencies and Commitments (Details) $ in Thousands			1 Months Ended			12 Months Ended
	Jul. 31, 2014 USD ($)	Mar. 20, 2014 USD ($)	Jan. 31, 2017 USD ($)	Mar. 31, 2011 USD ($)	Jun. 30, 2003 USD ($)	Dec. 31, 2017 USD ($) ft²	Dec. 31, 2009 USD ($) property	Dec. 31, 2016 USD ($)	May 31, 2012 USD ($)	Sep. 30, 2011 USD ($)	Jul. 31, 2010 USD ($)	May 31, 2010 USD ($)	Mar. 31, 2010 USD ($)	Jun. 30, 2009 USD ($)	Feb. 28, 2006 USD ($)
Contingencies and Commitments
Contract receivables						$ 1,801,656		$ 1,743,300
Long Island Expressway/Cross Island Parkway Matter
Contingencies and Commitments
Estimated value of project completed in Feb. 2006															$ 130,000
Value of claim filed				$ 53,800
Amount receivable as per final agreement										$ 500
Value of counterclaim filed									$ 151,000
Fontainebleau Matter
Contingencies and Commitments
Number of rooms in hotel/casino complex | property							3,800
Total outstanding liens on property, including subcontractors' liens														$ 44,000
Amount of court order in favor of plaintiff												$ 45,000
Amount set aside from approved sale for distribution to satisfy creditor claims											$ 125,000
Estimated sustainable lien amount											$ 350,000
Honeywell Street/Queens Boulevard Bridges Matter
Contingencies and Commitments
Value of claim filed					$ 8,800
Value of counterclaim filed													$ 74,600
Release of retention plus interest from 2010			$ 1,200
Westgate Planet Hollywood Matter
Contingencies and Commitments
Settlement on judgment		$ 19,700
Value of counterclaim filed							$ 45,000
Total outstanding liens on property, including subcontractors' liens							23,200
Settlement receipt						$ 16,000
Value of mechanic's lien release bond	$ 22,300						22,300
Value of cross complaint filed							$ 51,000
Damages awarded to WPH which are anticipated to be paid by the OCIP carrier		$ 3,100
Value of supersedeas bond	1,700
Total value of security	$ 24,000
Loss Contingency, Estimated Recovery from Third Party						$20
U.S. Department of Commerce, National Oceanic and Atmospheric Administration Matter [Member]
Contingencies and Commitments
Square footage of facility | ft²						287,000