Investments in Affiliates (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	$ 33,077	$ 34,177	$ 33,077	$ 34,177	$ 32,361
Joint Venture Unconsolidated [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	33,077	34,177	33,077	34,177	32,361
Equity Method Investment, Summarized Financial Information, Assets	179,949	172,220	179,949	172,220	170,174
Equity Method Investments Summarized Financial Information Net Assets	106,239	103,651	106,239	103,651	97,639
Equity Method Investments	18,400	17,800	18,400	17,800	16,500
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Investments in and Advances to Affiliates [Line Items]
Unconsolidated Construction Joint Venture Revenue	$ 530,215	313,945	$ 1,439,766	1,055,276
Number of projects	11		11
Unconsolidated Construction Joint Venture Cost of Revenue	$ 424,492	338,848	$ 1,270,793	982,014
Joint Venture Unconsolidated [Member] | Other Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	8,984	10,137	8,984	10,137	9,738
Equity Method Investments	33,077	34,177	33,077	34,177	32,361
Joint Venture Unconsolidated [Member] | Equity Method investments in Real Estate Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	24,093	24,040	24,093	24,040	$ 22,623
Joint Venture Unconsolidated [Member] | Minimum [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	19,200		19,200
Joint Venture Unconsolidated [Member] | Minimum [Member] | Real Estate Entities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Real Estate Development Projects Range of Total Assets	1,700		1,700
Joint Venture Unconsolidated [Member] | Maximum [Member] | Real Estate Entities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Real Estate Development Projects Range of Total Assets	69,600		69,600
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Investments in and Advances to Affiliates [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]
Investments in and Advances to Affiliates [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