Construction and Line Item Joint Ventures - Unconsolidated Construction Joint Ventures (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Construction Joint Venture [Line Items]
Equity in construction joint ventures	$ 107,821,000		$ 87,653,000		$ 107,821,000		$ 87,653,000		$ 101,029,000
Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	4				4
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,900,000,000				1,900,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	2				2
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	9				9
Unconsolidated Construction Joint Venture Revenue	663,536,000		224,498,000		869,368,000		424,266,000
Unconsolidated Construction Joint Venture Cost of Revenue	544,838,000		183,130,000		714,450,000		334,010,000
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	245,707,000		230,224,000		245,707,000		230,224,000		238,603,000
Unconsolidated Construction Joint Venture Liabilities	137,886,000		142,571,000		137,886,000		142,571,000		137,574,000
Unconsolidated Construction Joint Venture Revenue	100,234,000		60,566,000		173,863,000		133,988,000
Unconsolidated Construction Joint Venture Cost of Revenue	77,298,000		54,635,000		137,670,000		103,651,000
Unconsolidated Construction Joint Venture Gross Profit Loss	22,936,000		5,931,000		36,193,000		30,337,000
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	700,000,000				700,000,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	392,139,000		357,929,000		392,139,000		357,929,000		364,979,000
Unconsolidated Construction Joint Venture Liabilities	238,234,000		242,514,000		238,234,000		242,514,000		236,746,000
Unconsolidated Construction Joint Venture Revenue	563,302,000	[1]	163,932,000	[1]	695,505,000	[1]	290,278,000	[1]
Unconsolidated Construction Joint Venture Cost of Revenue	467,540,000	[1]	128,495,000	[1]	576,780,000	[1]	230,359,000	[1]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,200,000,000				1,200,000,000
Minimum [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	5,600,000				5,600,000
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	246,000,000				246,000,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	45.00%				45.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	57,800,000				57,800,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%				20.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	54,100,000				54,100,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	500,000				500,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	21,500,000				21,500,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	319,300,000				319,300,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	60.00%				60.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	1,200,000,000				1,200,000,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%				50.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	130,000,000				130,000,000
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	35,500,000				35,500,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	212,000,000				212,000,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	54,900,000				54,900,000
Cash and Cash Equivalents [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	337,102,000	[1]	382,745,000	[1]	337,102,000	[1]	382,745,000	[1]	338,681,000	[1]
Other Assets, Current and Longterm [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	300,744,000		205,408,000		300,744,000		205,408,000		264,901,000
Accounts Payable [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	101,782,000		85,505,000		101,782,000		85,505,000		85,075,000
Billings in Excess of Costs and Estimated Earnings [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	265,883,000	[1]	290,584,000	[1]	265,883,000	[1]	290,584,000	[1]	280,650,000	[1]
Accrued Liabilities [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	$ 8,455,000		$ 8,996,000		$ 8,455,000		$ 8,996,000		$ 8,595,000

[1] The volume and stage of completion of contracts from our unconsolidated construction joint ventures may cause fluctuations in cash and cash equivalents, as well as billings in excess of costs and estimated earnings between periods.