Commitments and Contingencies (Narrative) (Details) $ in Thousands	1 Months Ended						3 Months Ended
	Mar. 31, 2016 USD ($)	Jun. 30, 2015 USD ($)	Oct. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Jan. 31, 2010 USD ($)	Jun. 30, 2009 USD ($) room	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	May 31, 2012 USD ($)	Sep. 30, 2011 USD ($)	May 31, 2010 USD ($)	Feb. 28, 2006 USD ($)
Loss Contingencies [Line Items]
Proceeds from sale of property and equipment							$ 201	$ 3,303
Long Island Expressway/Cross Island Parkway Matter [Member]
Loss Contingencies [Line Items]
Estimated value of project completed in Feb. 2006												$ 130,000
Value of claim filed				$ 50,700
Amount receivable as per final agreement										$ 500
Value of counterclaim filed									$ 151,000
Fontainebleau Matter [Member]
Loss Contingencies [Line Items]
Number of rooms in hotel/casino complex | room						3,800
Amount of court order in favor of plaintiff											$ 45,000
Proceeds from sale of property and equipment			$ 85,000		$ 150,000
Total outstanding liens on property, including subcontractors' liens						$ 44,000
Fontainebleau Matter [Member] | Other Unaffiliated Contractors Subcontractors And Suppliers [Member]
Loss Contingencies [Line Items]
Total outstanding liens on property, including subcontractors' liens						$ 550,000
Alaska Way Viaduct Matter [Member]
Loss Contingencies [Line Items]
Value of claim filed	$ 57,200	$ 532,000
Value of counterclaim filed	$ 667,000