Construction and Line Item Joint Ventures - Schedule of Unconsolidated Construction Joint Ventures Revenue and Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Variable Interest Entity [Line Items]
Deficit in unconsolidatedconstruction joint venture	$ 13,100		$ 13,100
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue	530,215	$ 313,945	1,439,766	$ 1,055,276
Unconsolidated Construction Joint Venture Cost of Revenue	424,492	338,848	1,270,793	982,014
Other Partners Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue	382,465	213,068	1,018,565	741,451
Unconsolidated Construction Joint Venture Cost of Revenue	287,784	239,661	879,653	696,633
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue	147,750	100,877	421,201	313,825
Unconsolidated Construction Joint Venture Cost of Revenue	136,708	99,187	391,140	285,381
Unconsolidated Construction Joint Venture Gross Profit Loss	$ 11,042	$ 1,690	$ 30,061	$ 28,444